beam model calculation

60
E E U U R R O O C C O O D D E E 2 2 W W O O R R K K E E D D E E X X A A M M P P L L E E S S

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Calculation of beams accordig to EC2

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Page 1: Beam Model Calculation

EEUU

RROO

CCOO

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22

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SS

Page 2: Beam Model Calculation

EEUU

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CCOO

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RRKK

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SS

Cop

yrig

ht:

Euro

pean

Con

cret

eP

latf

orm

ASB

L,M

ay20

08.

Allr

ight

sre

serv

ed.N

opa

rtof

this

publ

icat

ion

may

bere

prod

uced

,sto

red

ina

retr

ieva

lsys

tem

ortr

ansm

itted

inan

yfo

rmor

byan

ym

eans

,el

ectr

onic

,m

echa

nica

l,ph

otoc

opyi

ng,

reco

rdin

gor

othe

rwis

e,w

ithou

tth

epr

ior

writ

ten

perm

issi

onof

the

Euro

pean

Conc

rete

Plat

form

ASBL

.

Publ

ishe

dby

the

Euro

pean

Conc

rete

Plat

form

ASBL

Edito

r:Je

an-P

ierr

eJa

cobs

8ru

eVo

lta10

50Br

usse

ls,B

elgi

um

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ut&

Prin

ting

byth

eEu

rope

anCo

ncre

tePl

atfo

rm

Alli

nfor

mat

ion

inth

isdo

cum

ent

isde

emed

tobe

accu

rate

byth

eEu

rope

anCo

ncre

tePl

atfo

rmAS

BLat

the

time

ofgo

ing

into

pres

s.It

isgi

ven

ingo

odfa

ith.

Info

rmat

ion

onEu

rope

anCo

ncre

tePl

atfo

rmdo

cum

ents

does

not

crea

tean

ylia

bilit

yfo

rits

Mem

bers

.W

hile

the

goal

isto

keep

this

info

rmat

ion

timel

yan

dac

cura

te,

the

Euro

pean

Conc

rete

Plat

form

ASBL

cann

otgu

aran

tee

eith

er.

Ifer

rors

are

brou

ght

toits

atte

ntio

n,th

eyw

illbe

corr

ecte

d.

The

opin

ions

refle

cted

inth

isdo

cum

ent

are

thos

eof

the

auth

ors

and

the

Euro

pean

Conc

rete

Plat

form

ASBL

cann

otbe

held

liabl

efo

ran

yvi

ewex

pres

sed

ther

ein.

All

advi

ceor

info

rmat

ion

from

the

Euro

pean

Conc

rete

Plat

form

ASBL

isin

tend

edfo

rth

ose

who

will

eval

uate

the

sign

ifica

nce

and

limita

tions

ofits

cont

ents

and

take

resp

onsi

bilit

yfo

rits

use

and

appl

icat

ion.

No

liabi

lity

(incl

udin

gfo

rne

glig

ence

)fo

ran

ylo

ssre

sulti

ngfr

omsu

chad

vice

orin

form

atio

nis

acce

pted

.

Read

ers

shou

ldno

teth

atal

lEur

opea

nCo

ncre

tePl

atfo

rmpu

blic

atio

nsar

esu

bjec

tto

revi

sion

from

time

totim

ean

dth

eref

ore

ensu

reth

atth

eyar

ein

poss

essi

onof

the

late

stve

rsio

n.

This

publ

icat

ion

isba

sed

onth

epu

blic

atio

n:"G

uida

all'u

sode

ll'eu

roco

dice

2"pr

epar

edby

AICA

P;th

eIt

alia

nAs

soci

atio

nfo

rRe

info

rced

and

Pres

tres

sed

Conc

rete

,on

beha

lfof

the

the

Ital

ian

Cem

ent

Org

anzi

atio

nAI

TEC,

and

onba

ckgr

ound

docu

men

tspr

epar

edby

the

Euro

code

2Pr

ojec

tTe

ams

Mem

bers

,du

ring

the

prep

arat

ion

ofth

eEN

vers

ion

ofEu

roco

de2

(pro

fA.

W.

Beeb

y,pr

ofH

.Co

rres

Peire

tti,

prof

J.W

alra

ven,

prof

B.W

este

rber

g,pr

ofR.

V.W

hitm

an).

Auth

oriz

atio

nha

sbe

enre

ceiv

edor

ispe

ndin

gfr

omor

gani

satio

nsor

indi

vidu

als

for

thei

rsp

ecifi

cco

ntrib

utio

ns.

Page 3: Beam Model Calculation
Page 4: Beam Model Calculation

Att

ribu

tabl

eFo

rew

ord

toth

eC

omm

enta

ryan

dW

orke

dE

xam

ples

toE

C2

Euro

code

sar

eon

eof

the

mos

tadv

ance

dsu

iteof

stru

ctur

alco

des

inth

ew

orld

.The

yem

body

the

colle

ctiv

eex

perie

nce

and

know

ledg

eof

who

leof

Euro

pe.T

hey

are

born

out

ofan

ambi

tious

prog

ram

me

initi

ated

byth

eEu

rope

anU

nion

.With

aw

ealth

ofco

dew

ritin

gex

perie

nce

inEu

rope

,itw

aspo

ssib

leto

appr

oach

the

task

ina

ratio

nal

and

logi

calm

anne

r.Eu

roco

des

refle

ctth

ere

sults

ofre

sear

chin

mat

eria

ltec

hnol

ogy

and

stru

ctur

albe

havi

our

inth

ela

stfif

tyye

ars

and

they

inco

rpor

ate

allm

oder

ntre

nds

inst

ruct

ural

desi

gn.

Like

man

ycu

rren

tna

tiona

lco

des

inEu

rope

,Eu

roco

de2

(EC

2)fo

rco

ncre

test

ruct

ures

draw

she

avily

onth

eC

EBM

odel

Cod

e.A

ndye

tth

epr

esen

tatio

nan

dte

rmin

olog

y,co

nditi

oned

byth

eag

reed

form

atfo

rEu

roco

des,

mig

htob

scur

eth

esi

mila

ritie

sto

man

yna

tiona

lco

des.

Als

oEC

2in

com

mon

with

othe

rEu

roco

des,

tend

sto

bege

nera

lin

char

acte

rand

this

mig

htpr

esen

tdiff

icul

tyto

som

ede

sign

ers

atle

ast

initi

ally

.Th

epr

oble

ms

ofco

min

gto

term

sw

itha

new

set

ofco

des

bybu

sypr

actis

ing

engi

neer

sca

nnot

beun

dere

stim

ated

.Thi

sis

the

back

drop

toth

epu

blic

atio

nof

‘Com

men

tary

and

Wor

ked

Exam

ples

toEC

2’by

Prof

esso

rM

anci

nian

dhi

sco

lleag

ues.

Com

mis

sion

edby

CEM

BU

REA

U,

BIB

M,

EFC

Aan

dER

MC

Oth

ispu

blic

atio

nsh

ould

prov

eim

men

sely

valu

able

tode

sign

ers

indi

scov

erin

gth

eba

ckgr

ound

tom

any

ofth

eco

dere

quire

men

ts.T

his

publ

icat

ion

will

assi

stin

build

ing

conf

iden

cein

the

new

code

,w

hich

offe

rsto

ols

for

the

desi

gnof

econ

omic

and

inno

vativ

eco

ncre

test

ruct

ures

.Th

epu

blic

atio

nbr

ings

toge

ther

man

yof

the

docu

men

tspr

oduc

edby

the

Proj

ect

Team

durin

gth

ede

velo

pmen

tof

the

code

.The

docu

men

tis

rich

inth

eore

tical

expl

anat

ions

and

draw

son

muc

hre

cent

rese

arch

.C

ompa

rison

sw

ithth

eEN

Vst

age

ofEC

2ar

eal

sopr

ovid

edin

anu

mbe

rofc

ases

.The

chap

ter

onEN

1990

(Bas

isof

stru

ctur

alde

sign

)is

anad

ded

bonu

san

dw

illbe

appr

ecia

ted

bypr

actio

ners

.Wor

ked

exam

ples

furth

erill

ustra

teth

eap

plic

atio

nof

the

code

and

shou

ldpr

omot

eun

ders

tand

ing.

The

com

men

tary

will

prov

ean

auth

entic

com

pani

onto

EC2

and

dese

rves

ever

ysu

cces

s.

Prof

esso

rRS

Nar

ayan

anC

hairm

anC

EN/T

C25

0/SC

2(2

002

–20

05)

Fore

wor

dto

Com

men

tary

toEu

roco

de2

and

Wor

ked

Exam

ples

Whe

na

new

code

ism

ade,

oran

exis

ting

code

isup

date

d,a

num

bero

fprin

cipl

essh

ould

bere

gard

ed:

1.C

odes

shou

ldbe

base

don

clea

ran

dsc

ient

ifica

llyw

ell

foun

ded

theo

ries,

cons

iste

ntan

dco

here

nt,c

orre

spon

ding

toa

good

repr

esen

tatio

nof

the

stru

ctur

albe

havi

oura

ndof

the

mat

eria

lphy

sics.

2.C

odes

shou

ldbe

trans

pare

nt.T

hatm

eans

that

the

writ

erss

houl

dbe

awar

e,th

atth

eco

deis

notp

repa

red

fort

hose

who

mak

eit,

butf

orth

ose

who

will

use

it.3.

New

deve

lopm

ents

shou

ldbe

reco

gniz

edas

muc

has

poss

ible

,but

nota

tthe

cost

ofto

oco

mpl

exth

eore

tical

form

ulat

ions

.4.

Aco

desh

ould

beop

en-m

inde

d,w

hich

mea

nsth

atit

cann

otbe

base

don

one

certa

inth

eory

,exc

ludi

ngot

hers

.Mod

elsw

ithdi

ffer

entd

egre

esof

com

plex

itym

aybe

offe

red.

5.A

code

shou

ldbe

sim

ple

enou

ghto

beha

ndle

dby

prac

ticin

gen

gine

ers

with

out

cons

ider

able

prob

lem

s.O

nth

eot

herh

and

sim

plic

itysh

ould

notl

ead

tosi

gnifi

cant

lack

ofac

cura

cy.H

ere

the

wor

d“a

ccur

acy”

shou

ldbe

wel

lund

erst

ood.

Ofte

nso

-ca

lled

“acc

urat

e”fo

rmul

atio

ns,d

eriv

edby

scie

ntist

s,ca

nnot

lead

tove

ryac

cura

tere

sults

,bec

ause

the

inpu

tval

uesc

anno

tbe

estim

ated

with

accu

racy

.6.

Aco

dem

ayha

vedi

ffer

entl

evel

sof

soph

istic

atio

n.Fo

rins

tanc

esi

mpl

e,pr

actic

alru

les

can

begi

ven,

lead

ing

toco

nser

vativ

ean

dro

bust

desi

gns.

As

anal

tern

ativ

em

ore

deta

iled

desi

gnru

les

may

beof

fere

d,co

nsum

ing

mor

eca

lcul

atio

ntim

e,bu

tre

sulti

ngin

mor

eac

cura

tean

dec

onom

icre

sults

.

Forw

ritin

ga

Euro

code

,lik

eEC

-2,a

noth

erim

porta

ntco

nditi

onap

plie

s.In

tern

atio

nal

cons

ensu

shad

tobe

reac

hed,

butn

oton

the

cost

ofsi

gnifi

cant

conc

essi

onsw

ithre

gard

toqu

ality

.Alo

tofe

ffor

twas

inve

sted

toac

hiev

eal

ltho

sego

als.

Itis

aru

lefo

rev

ery

proj

ect,

that

itsh

ould

not

beco

nsid

ered

asfin

aliz

edif

impl

emen

tatio

nha

sno

tbe

enta

ken

care

of.

This

book

may

,fu

rther

toco

urse

san

dtra

inin

gson

ana

tiona

lan

din

tern

atio

nal

leve

l,se

rve

asan

esse

ntia

lan

dva

luab

leco

ntrib

utio

nto

this

impl

emen

tatio

n.It

cont

ains

exte

nsiv

eba

ckgr

ound

info

rmat

ion

onth

ere

com

men

datio

nsan

dru

les

foun

din

EC2.

Itis

impo

rtant

that

this

back

grou

ndin

form

atio

nis

wel

ldo

cum

ente

dan

dpr

actic

ally

avai

labl

e,as

such

incr

easi

ngth

etra

nspa

renc

y.Iw

ould

like

toth

ank

my

colle

ague

sof

the

Proj

ectT

eam

,esp

ecia

llyR

obin

Whi

ttle,

BoW

este

rber

g,H

ugo

Cor

res

and

Kon

rad

Zilc

h,fo

rhe

lpin

gin

getti

ngto

geth

eral

lbac

kgro

und

info

rmat

ion.

Als

om

yco

lleag

ueG

iuse

ppe

Man

cini

and

his

Italia

nte

amar

egr

atef

ully

ackn

owle

dged

forp

rovi

ding

ase

tofv

ery

illus

trativ

ean

dpr

actic

alw

orki

ngex

ampl

es.F

inal

lyI

wou

ldlik

eto

than

kCE

MB

UR

AU

,BIB

M,E

FCA

and

ERM

COfo

rth

eiri

nitia

tive,

supp

orta

ndad

vice

tobr

ing

outt

hisp

ublic

atio

n.

Joos

tWal

rave

nC

onve

noro

fPro

ject

Team

forE

C2(1

998

-200

2)

Page 5: Beam Model Calculation

EC2�

wor

ked

exam

ples

sum

mar

y

Tabl

eof

Cont

ent

EU

RO

CO

DE

2-W

OR

KE

DE

XA

MPL

ES

-SU

MM

AR

Y

SEC

TIO

N2.

WO

RK

ED

EXA

MPL

ES–

BA

SIS

OF

DE

SIG

N...

......

......

......

......

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......

......

..2-

1

EXA

MPL

E2.

1.U

LSCO

MBI

NAT

ION

SO

FAC

TIO

NS

FOR

ACO

NTI

NU

OU

SBE

AM[E

C2

–CL

AUSE

2.4]

......

......

......

......

......

.2-1

EXA

MPL

E2.

2.U

LSCO

MBI

NAT

ION

SO

FAC

TIO

NS

FOR

ACA

NO

PY[E

C2

–CL

AUSE

2.4]

......

......

......

......

......

......

......

......

.2-2

EXA

MPL

E2.

3.U

LSCO

MBI

NAT

ION

OF

ACTI

ON

OF

ARE

SID

ENTI

ALCO

NCR

ETE

FRAM

EDBU

ILD

ING

[EC

2–

CLAU

SE2.

4]...

......

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..2-4

EXA

MPL

E2.

4.U

LSCO

MBI

NAT

ION

SO

FAC

TIO

NS

ON

ARE

INFO

RCED

CON

CRET

ERE

TAIN

ING

WAL

L

[EC

2–

CLAU

SE2.

4]...

......

......

......

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...2-

6

EXA

MPL

E2.

5.C

ON

CRET

ERE

TAIN

ING

WAL

L:G

LOBA

LST

ABIL

ITY

AND

GRO

UN

DRE

SIST

ANCE

VERI

FICA

TIO

NS

[EC

2–

CLAU

SE2.

4]...

......

......

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...2-

9

SEC

TIO

N4.

WO

RK

EDE

XA

MPL

ES–

DU

RA

BIL

ITY

......

......

......

......

......

......

......

......

......

......

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......

..4-

1

EXA

MPL

E4.

1[E

C2

CLAU

SE4.

4]...

......

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......

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....4

-1

EXA

MPL

E4.

2[E

C2

CLAU

SE4.

4]...

......

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-3

EXA

MPL

E4.

3[E

C2

CLAU

SE4.

4]...

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....4

-4

SEC

TIO

N6.

WO

RK

EDE

XA

MPL

ES

–U

LTIM

AT

EL

IMIT

STA

TES

......

......

......

......

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......

6-1

EXA

MPL

E6.

1(C

ON

CRET

EC

30/3

7)[E

C2

CLAU

SE6.

1]...

......

......

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.6-1

EXA

MPL

E6.

2(C

ON

CRET

EC

90/1

05)[

EC

2CL

AUSE

6.1]

......

......

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..6-3

EXA

MPL

E6.

3C

ALCU

LATI

ON

OF

VRD

,CFO

RA

PRES

TRES

SED

BEAM

[EC

2CL

AUSE

6.2]

......

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6-4

EXA

MPL

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4D

ETER

MIN

ATIO

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RESI

STAN

CEG

IVEN

THE

SECT

ION

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MET

RYAN

DM

ECH

ANIC

S

[EC

2CL

AUSE

6.2]

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5

EXA

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E6.

4B–

THE

SAM

EAB

OVE

,WIT

HST

EEL

S500

Cf yd

=43

5M

PA.[

EC

2CL

AUSE

6.2]

......

......

......

......

......

......

..6-7

EXA

MPL

E6.

5[E

C2

CLAU

SE6.

2]...

......

......

......

......

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......

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......

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......

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-9

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EXA

MPL

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S[E

C2

CLAU

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......

......

......

......

......

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.6-1

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EXA

MPL

E6.

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2CL

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6.5]

......

......

......

......

......

......

......

......

......

......

......

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......

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......

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...6-

15

EC2�

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ked

exam

ples

sum

mar

y

Tabl

eof

Cont

ent

EXA

MPL

E6.

9.TH

ICK

SHO

RTC

ORB

EL,a

<Z/2

[EC

2CL

AUSE

6.5]

......

......

......

......

......

......

......

......

......

......

......

......

......

.6-1

8

EXA

MPL

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10TH

ICK

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TILE

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5]...

......

......

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EXA

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....6

-28

EXA

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5]...

......

......

......

......

......

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......

......

......

......

......

......

...6-

32

EXA

MPL

E6.

14.3

500

KNCO

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NTR

ATED

LOAD

[EC

2CL

AUSE

6.5]

......

......

......

......

......

......

......

......

......

......

......

......

6-38

EXA

MPL

E6.

15SL

ABS, [E

C2

CLAU

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10–

6.1

–6.

2–

7.2

–7.

3–

7.4]

......

......

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0

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TE

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RK

ED

EXA

MPL

ES...

......

......

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......

......

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1

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MPL

E7.

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VALU

ATIO

NO

FSE

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RESS

ES[E

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2]...

......

......

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..7-1

EXA

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E7.

2D

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5

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E7.

3E

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ATIO

NO

FCR

ACK

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ITU

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4]...

......

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.....7

-8

EXA

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E7.

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NFO

RMU

LAS

DER

IVAT

ION

FOR

THE

CRAC

KIN

GLI

MIT

STAT

E

[EC

2CL

AUSE

7.4]

......

......

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5B7.

4.2

APP

ROXI

MAT

EDM

ETH

OD

......

......

......

......

......

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......

......

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......

......

......

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......

......

......

......

.7-1

1

EXA

MPL

E7.

5A

PPLI

CATI

ON

OF

THE

APPR

OXI

MAT

EDM

ETH

OD

[EC

2CL

AUSE

7.4]

......

......

......

......

......

......

......

......

....7

-13

EXA

MPL

E7.

6V

ERIF

ICAT

ION

OF

LIM

ITST

ATE

OF

DEF

ORM

ATIO

N...

......

......

......

......

......

......

......

......

......

......

......

......

..7-1

8

SEC

TIO

N11

.LIG

HT

WE

IGH

TC

ON

CR

ETE

–W

OR

KE

DEX

AM

PLE

S....

......

......

......

......

......

......

...11

-1

EXA

MPL

E11

.1[E

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USE

11.3

.1–

11.3

.2]..

......

......

......

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.11-

1

EXA

MPL

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11.3

.5–

11.3

.6–

11.4

–11

.6].

......

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...11

-3

Page 6: Beam Model Calculation

EC2�

wor

ked

exam

ples

2-1

Tabl

eof

Cont

ent

SEC

TIO

N2.

WO

RK

ED

EX

AM

PLE

S–

BA

SIS

OF

DE

SIG

N

EX

AM

PL

E2.

1.U

LS

com

bina

tions

ofac

tions

fora

cont

inuo

usbe

am[E

C2�

clau

se2.

4]

Aco

ntin

uous

beam

onfo

urbe

arin

gsis

subj

ecte

dto

the

follo

win

glo

ads:

Self-

wei

ght

Gk1

Perm

anen

tim

pose

dlo

adG

k2Se

rvice

impo

sed

load

Qk1

Note

.In

this

exam

ple

and

inth

efol

lowin

gon

es,a

single

char

acter

istic

valu

eis

take

nfor

self-w

eight

and

perm

anen

timp

osed

load,

respe

ctive

lyG

k1an

dG

k2,b

ecaus

eoft

heir

smal

lvar

iabi

lity.

EQ

U�

Stat

iceq

uilib

rium

(Set

A)

Fact

ors

ofSe

tAsh

ould

beus

edin

the

verif

icat

ion

ofho

ldin

gdo

wn

devi

ces

for

the

uplif

tof

bear

ings

aten

dsp

an,a

sind

icate

din

Fig.

2.1.

Fig.

2.1.

Loa

dco

mbin

ation

forver

ifica

tion

ofho

lding

down

devic

esat

thee

ndbe

arin

gs.

STR�

Bend

ingm

omen

tveri

ficat

ionat

mid

span

(Set

B)

Unl

ike

inth

eve

rific

atio

nof

stat

iceq

uilib

rium

,the

parti

alsa

fety

fact

orfo

rper

man

entl

oads

inth

eve

rific

atio

nof

bend

ing

mom

enti

nth

em

iddl

eof

the

cent

rals

pan,

isth

esa

me

fora

llsp

ans:

G=

1.35

(Fig

.2.2

). Fig.

2.2.

Loa

dcom

bina

tion

forve

rifica

tion

ofbe

ndin

gmom

enti

nth

eBC

span

.

EC2�

wor

ked

exam

ples

2-2

Tabl

eof

Cont

ent

EX

AM

PL

E2.

2.U

LS

com

bina

tions

ofac

tions

fora

cano

py[E

C2�

clau

se2.

4]

The

cano

pyis

subj

ecte

dto

the

follo

win

glo

ads:

Self-

wei

ght

Gk1

Perm

anen

tim

pose

dlo

adG

k2Sn

owim

pose

dlo

adQ

k1

EQ

U�

Stat

iceq

uilib

rium

(Set

A)

Fact

orst

obe

take

nfo

rthe

verif

icat

ion

ofov

ertu

rnin

gar

eth

ose

ofSe

tA,a

sin

Fig.

2.3.

Fig.

2.3.

Loa

dcom

bina

tion

forve

rifica

tion

ofsta

ticeq

uilib

rium

.

STR�

Veri

ficat

ionof

resist

ance

ofa

colu

mn(

SetB

)

The

parti

alfa

ctor

tobe

take

nfo

rpe

rman

ent

load

sin

the

verif

icatio

nof

max

imum

com

pres

sion

stre

sses

and

ofbe

ndin

gw

ithax

ialfo

rce

inth

eco

lum

nis

the

sam

e(

G=

1.35

)for

allsp

ans.

The

varia

ble

impo

sed

load

isdi

strib

uted

over

the

full

leng

thof

the

cano

pyin

the

first

case

,an

don

lyon

half

ofit

fort

heve

rific

atio

nof

bend

ing

with

axia

lfor

ce.

Page 7: Beam Model Calculation

EC2�

wor

ked

exam

ples

2-3

Tabl

eof

Cont

ent

Fig.

2.4.

Loa

dco

mbin

ation

forth

ecom

press

ionstr

esses

verif

icatio

nof

thec

olum

n.

Fig.

2.5.

Loa

dcom

bina

tion

forth

everi

ficat

ionof

bend

ingw

ithax

ialf

orce

ofth

ecolu

mn.

EC2�

wor

ked

exam

ples

2-4

Tabl

eof

Cont

ent

EX

AM

PL

E2.

3.U

LS

com

bina

tion

ofac

tion

-re

side

ntia

lco

ncre

tefr

amed

build

ing

[EC

2�

clau

se2.

4]

The

perm

anen

tim

pose

dlo

adis

indi

cate

das

Gk.V

ariab

leac

tions

are

liste

din

tabl

e2.

1.T

able

2.1.

Var

iable

actio

nson

ares

iden

tialc

oncre

tebu

ildin

g.V

aria

blea

ction

sse

rvic

eabi

lity

impo

sed

load

snow

onro

ofin

g(fo

rsite

sund

er10

00m

a.s.l

.)w

ind

Cha

racte

ristic

valu

eQk

Qk,

esQ

k,n

F k,w

Com

bina

tion

valu

e0

Qk

0.7

Qk,

es0.

5Q

k,n

0.6

F k,w

N.B

.The

valu

esof

parti

alfa

ctors

aret

hose

recom

mend

edby

EN

1990

,but

they

may

bede

fined

inth

eNat

ional

Ann

ex.

Basic

com

bina

tions

forth

everi

ficat

ionof

thes

upers

tructu

re-S

TR(S

etB)

(eq.6

.10-

EN

1990

)Pr

edom

inan

tact

ion:

win

dfa

vour

able

verti

call

oads

(fig.

2.6,

a)1.

0·G

k+

1.5·

F k,w

unfav

oura

blev

ertica

lloa

ds(fi

g.2.

6,b)

1.35

·Gk

+1.

5·(F

k,w

+0.

5·Q

k,n

+0.

7·Q

k,es

)=1.

35·G

k+

1.5·

F k,w

+0.

75·Q

k,n

+1.

05·Q

k,es

Pred

omin

anta

ctio

n:sn

ow(fi

g.2.

6,c)

1.35

·Gk

+1.

5·(Q

k,n+

0.7·

Qk,

es+

0.6·

F k,w

)=1.

35·G

k+

1.5·

Qk,

n+

1.05

·Qk,

es+

0.9·

F k,w

Pred

omin

anta

ctio

n:se

rvice

load

(fig.

2.6,

d)1.

35·G

k+

1.5·

(Qk,

es+

0.5·

Qk,

n+

0.6·

F k,w

)=1.

35·G

k+

1.5·

Qk,

es+

0.75

·Qk,

n+

0.9·

F k,w

Fig.

2.6.

Basic

comb

inat

ionsf

orth

everi

ficat

ionof

thes

upers

tructu

re(S

etB)

:a)W

ind

pred

omin

ant,

favou

rabl

evert

icall

oads

;b)

Win

dpr

edom

inan

t,un

favo

urab

leve

rtica

lloa

ds;c

)Sno

wloa

dpr

edom

inan

t;d)

servic

eloa

dpr

edom

inan

t.

Page 8: Beam Model Calculation

EC2�

wor

ked

exam

ples

2-5

Tabl

eof

Cont

ent

Basic

com

bina

tions

forth

everi

ficat

ionof

found

ation

sand

grou

ndres

istan

ce�

STR

/GE

O[eq

.6.1

0-E

N19

90]

EN

1990

allo

ws

for

thre

edi

ffer

ent

appr

oach

es;

the

appr

oach

tobe

used

isch

osen

inth

eN

atio

nalA

nnex

.For

com

plet

enes

sand

inor

dert

ocla

rify

wha

tis

indi

cate

din

Tabl

es2.

15an

d2.

16,t

heba

sicco

mbi

natio

nsof

actio

nsfo

rall

the

thre

eap

proa

ches

prov

ided

byE

N19

90ar

egi

ven

belo

w.

App

roac

h1

The

desig

nva

lues

ofSe

tCan

dSe

tBof

geot

echn

ical

actio

nsan

dof

allot

hera

ctio

nsfr

omth

est

ruct

ure,

oron

the

stru

ctur

e,ar

eap

plie

din

sepa

rate

calc

ulat

ions

.Hea

vier

valu

esar

eus

ually

give

nby

SetC

fort

hege

otec

hnic

alve

rific

atio

ns(g

roun

dre

sista

nce

verif

icat

ion)

,and

bySe

tBfo

rthe

verif

icatio

nof

the

conc

rete

stru

ctur

alel

emen

tsof

the

foun

datio

n.

SetC

(geo

tech

nica

lver

ifica

tions

)

Pred

omin

anta

ctio

n:w

ind

(favo

urab

leve

rtica

lloa

ds)(

fig.2

.7,a

)1.

0·G

k+

1.3·

F k,w

Pred

omin

anta

ctio

n:w

ind

(unf

avou

rabl

eve

rtica

lloa

ds)(

fig.2

.7,b

)1.

0·G

k+

1.3·

F k,w

+1.

3·0.

5·Q

k,n+

1.3·

0.7·

Qk,

es=

1.0·

Gk

+1.

3·F k

,w+

0.65

·Qk,

n+

0.91

·Qk,

es

Pred

omin

anta

ctio

n:sn

ow(fi

g.2.

7,c)

1.0·

Gk

+1.

3·Q

k,n+

1.3·

0.7·

Qk,

es+

1.3·

0.6·

F k,w

=1.

0·G

k+

1.3·

Qk,

n+

0.91

·Qk,

es+

0.78

·Fk,

w

Pred

omin

anta

ctio

n:se

rvice

load

(fig.

2.7,

d)1.

0·G

k+

1.3·

Qk,

es+

1.3·

0.5·

Qk,

n+

1.3·

0.6·

F k,w

=1.

0·G

k+

1.3·

Qk,

n+

0.65

·Qk,

es+

0.78

·Fk,

w

Fig.

2.7.

Basic

combi

natio

nsfor

thev

erific

ation

ofth

efou

ndat

ions(

SetC

):a)

Win

dpr

edom

inan

t,fa

vour

able

verti

call

oads

;b)

Win

dpr

edom

inan

t,un

favo

urab

leve

rtica

lloa

ds;c

)Sno

wloa

dpr

edom

inan

t;d)

servic

eloa

dpr

edom

inan

t.

EC2�

wor

ked

exam

ples

2-6

Tabl

eof

Cont

ent

SetB

(ver

ifica

tion

ofco

ncre

test

ruct

ural

elem

ents

offo

unda

tions

)

1.0·

Gk

+1.

5·Q

k,w

1.35

·Gk

+1.

5·F k

,w+

0.75

·Qk,

n+

1.05

·Qk,

es

1.35

·Gk

+1.

5·Q

k,n

+1.

05·Q

k,es

+0.

9·F k

,w

1.35

·Gk

+1.

5·Q

k,es

+0.

75·Q

k,n

+0.

9·F k

,w

App

roac

h2

The

sam

eco

mbi

natio

nsus

edfo

rthe

supe

rstru

ctur

e(i.

e.Se

tB)a

reus

ed.

App

roac

h3

Fact

ors

from

SetC

forg

eote

chni

cala

ctio

nsan

dfr

omSe

tBfo

roth

erac

tions

are

used

inon

eca

lcul

atio

n.Th

isca

se,a

sge

otec

hnica

lact

ions

are

notp

rese

nt,c

anbe

refe

rred

toSe

tB,i

.e.to

appr

oach

2.

EX

AM

PL

E2.

4.U

LS

com

bina

tions

ofac

tions

ona

rein

forc

edco

ncre

tere

tain

ing

wal

l[E

C2�

clau

se2.

4]

Fig.

2.8.

Acti

onso

na

retain

ingw

alli

nrei

nfor

cedcon

crete

EQ

U-(

static

equi

libriu

mof

rigid

body

:veri

ficat

ionof

globa

lsta

bilit

yto

heav

eand

slidi

ng)(

SetA

)O

nly

that

part

ofth

eem

bank

men

tbe

yond

the

foun

datio

nfo

otin

gis

cons

ider

edfo

rth

eve

rific

atio

nof

glob

alst

abili

tyto

heav

ean

dsli

ding

(Fig

.2.9

).

1.1·

S k,te

rr+

0.9·

(Gk,

wal

l+G

k,te

rr)+

1.5·

S k,so

vr

Fig.

2.9.

Acti

onsf

orE

QU

ULS

verif

icatio

nof

aret

ainin

gwal

lin

reinf

orced

conc

rete

Page 9: Beam Model Calculation

EC2�

wor

ked

exam

ples

2-7

Tabl

eof

Cont

ent

STR

/GE

O-(

groun

dpr

essur

eand

verif

icatio

nof

resist

ance

ofwa

llan

dfoo

ting)

App

roac

h1

Des

ign

valu

esfro

mSe

tC

and

from

Set

Bar

eap

plie

din

sepa

rate

calcu

latio

nsto

the

geot

echn

icala

ctio

nsan

dto

allo

ther

actio

nsfr

omth

est

ruct

ure

oron

the

stru

ctur

e.

SetC

1.0·

S k,te

rr+

1.0·

Gk,

wal

l+1.

0·G

k,te

rr+

1.3·

S k,so

vr

SetB

1.35

·Sk,

terr

+1.

0·G

k,w

all+

1.0·

Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

1.35

·Sk,

terr

+1.

35·G

k,w

all+

1.35

·Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

1.35

·Sk,

terr

+1.

0·G

k,w

all+

1.35

·Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

1.35

·Sk,

terr

+1.

35·G

k,w

all+

1.0·

Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

Not

e:Fo

rall

the

abov

e-lis

ted

com

bina

tions

,tw

opo

ssib

ilitie

sm

ustb

eco

nsid

ered

:eith

erth

atth

esu

rcha

rge

conc

erns

only

the

part

ofem

bank

men

tbey

ond

the

foun

datio

nfo

otin

g(F

ig.2

.10a

),or

that

itac

tson

the

who

lesu

rfac

eof

the

emba

nkm

ent(

Fig.

2.10

b).

Fig.

2.10

.Pos

sible

load

cases

ofsu

rchar

geon

thee

mban

kmen

t.

Forb

revi

ty,o

nly

case

sin

relat

ion

with

case

b),i

.e.w

ithsu

rcha

rge

actin

gon

the

who

lesu

rfac

eof

emba

nkm

ent,

are

give

nbe

low

.

The

follo

win

gfig

ures

show

load

sin

relat

ion

toth

eco

mbi

natio

nsob

tain

edw

ithSe

tBpa

rtial

safe

tyfa

ctor

s.

EC2�

wor

ked

exam

ples

2-8

Tabl

eof

Cont

entFi

g.2.

11.A

ction

sfor

GE

O/S

TRU

LSve

rifica

tion

ofa

retai

ning

wall

inrei

nfor

cedco

ncret

e.

Page 10: Beam Model Calculation

EC2�

wor

ked

exam

ples

2-9

Tabl

eof

Cont

ent

App

roac

h2

SetB

isus

ed.

App

roac

h3

Fact

ors

from

SetC

forg

eote

chni

cala

ctio

nsan

dfr

omSe

tBfo

roth

erac

tions

are

used

inon

eca

lcul

atio

n.1.

0·S k

,terr

+1.

0·G

k,w

all+

1.0·

Gk,

terr

+1.

3·Q

k,so

vr+

1.3·

S k,so

vr

1.0·

S k,te

rr+

1.35

·Gk,

wal

l+1.

35·G

k,te

rr+

1.3·

Qk,

sovr

+1.

3·S k

,sovr

1.0·

S k,te

rr+

1.0·

Gk,

wal

l+1.

35·G

k,te

rr+

1.3·

Qk,

sovr

+1.

3·S k

,sovr

1.0·

S k,te

rr+

1.35

·Gk,

wal

l+1.

0·G

k,te

rr+

1.3·

Qk,

sovr

+1.

3·S k

,sovr

Anu

mer

icex

ampl

eis

give

nbe

low

.

EX

AM

PL

E2.

5.C

oncr

ete

reta

inin

gw

all:

glob

alst

abili

tyan

dgr

ound

resi

stan

ceve

rific

atio

ns[E

C2�

clau

se2.

4]

The

assu

mpt

ion

isin

itiall

ym

ade

that

the

surc

harg

eac

tson

lyon

the

part

ofem

bank

men

tbe

yond

the

foun

datio

nfo

otin

g.

Fig.

2.12

.Wall

dime

nsion

sand

actio

nson

thew

all(su

rchar

geou

tside

thef

ound

ation

footin

g).

wei

ghtd

ensit

y:=

18kN

/m3

angl

eof

shea

ring

resis

tanc

e:=

30°

fact

orof

horiz

.act

ive

earth

pres

sure

:K

a=

0.33

wal

l-gro

und

inte

rfac

efr

ictio

nan

gle:

=0°

self-

wei

ghto

fwal

l:P k

,wal

l=

0.30

2.50

25=

18.7

5kN

/mse

lf-w

eigh

toff

ootin

g:P k

,foot

=0.

502.

5025

=31

.25

kN/m

Gk,

wall

=P k

,wal

l+

P k,fo

ot=

18.7

5+

31.2

5=

50kN

/mse

lfw

eigh

tofg

roun

dab

ove

foot

ing:

Gk,

grou

nd=

182.

501.

70=

76.5

kN/m

surc

harg

eon

emba

nkm

ent:

Qk,

surc

h=

10kN

/m2

grou

ndho

rizon

talf

orce

:S k

,gro

und

=26

.73

kN/m

surc

harg

eho

rizon

talf

orce

:S k

,surc

h=

9.9

kN/m

EC2�

wor

ked

exam

ples

2-10

Tabl

eof

Cont

ent

Ver

ifica

tion

tofa

ilure

bysl

idin

g

Slid

efo

rce

Gro

und

horiz

onta

lfor

ce(

G=

1,1)

:S g

roun

d=

1.1

26.7

3=29

.40

kN/m

Surc

harg

eho

rizon

tal(

Q=

1.5)

:Ssu

r=

1.5

9.90

=14

.85

kN/m

Slid

ingf

orce:

F slid

e=

29.4

0+

14.8

5=

44.2

5kN

/m

Resis

tant

forc

e(in

the

assu

mpt

ion

ofgr

ound

-floo

ring

frict

ion

fact

or=

0.57

)w

alls

elf-w

eigh

t(G=

0.9)

:F s

tab,

wall

=0.

9(0

.57

18.7

5)=

9.62

kN/m

foot

ing

self-

wei

ght(

G=

0.9)

:F s

tab,

foot

=0.

9(0

.57

31.2

5)=

16.0

3kN

m/m

grou

ndse

lf-w

eigh

t(G=

0.9)

:F s

tab,

grou

nd=

0.9

(0.5

776

.5)=

39.2

4kN

/mres

istan

tfor

ce:F s

tab=

9.62

+16

.03

+39

.24

=64

.89

kN/m

The

safe

tyfa

ctor

fors

lidin

gis:

FS=

F sta

b/

F rib

=64

.89

/44

.25

=1.

466

Ver

ifica

tion

toO

vert

urni

ng

over

turn

ing

mom

ent

mom

entf

rom

grou

ndla

tera

lfor

ce(

G=

1.1)

:M

S,gr

ound

=1.

1(2

6.73

3.00

/3)=

29.4

0kN

m/m

mom

entf

rom

surc

harg

ela

tera

lfor

ce(

Q=

1.5)

:MS,

surc

h=

1.5

(9.9

01.

50)=

22.2

8kN

m/m

overt

urni

ngm

omen

t:M

rib=

29.4

0+

22.2

8=

51.6

8kN

m/m

stab

ilizin

gm

omen

tm

omen

twall

self-

weig

ht(

G=

0.9)

:M

stab

,wall

=0.

9(1

8.75

0.65

)=10

.97

kNm

/mm

omen

tfoo

ting

self-

weig

ht(

G=

0.9)

:M

stab

,foot

=0.

9(3

1.25

1.25

)=35

.16

kNm

/mm

omen

tgro

und

self-

weig

ht(

G=

0.9)

:M

stab

,gro

und

=0.

9(7

6.5

1.65

)=11

3.60

kNm

/msta

biliz

ingm

omen

t:M

stab=

10.9

7+

35.1

6+

113.

60=

159.

73kN

m/m

safe

tyfa

ctor

togl

obal

stab

ility

FS=

Mst

ab/M

rib=

159.

73/5

1.68

=3.

09

Con

tact

pres

sure

ongr

ound

App

roac

h2,

i.e.S

etB

ifpa

rtial

facto

rs,is

used

.

Byta

king

1.0

and

1.35

asth

epa

rtial

fact

ors

fort

hese

lf-w

eight

ofth

ew

allan

dof

the

grou

ndab

ove

the

foun

datio

nfo

otin

gre

spec

tivel

y,w

eob

tain

four

diff

eren

tco

mbi

natio

nsas

seen

abov

e:

first

com

bina

tion

1.35

·Sk,

terr

+1.

0·G

k,w

all+

1.0·

Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

seco

ndco

mbi

natio

n

1.35

·Sk,

terr

+1.

35·G

k,w

all+

1.35

·Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

third

com

bina

tion

1.35

·Sk,

terr

+1.

0·G

k,w

all+

1.35

·Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

Page 11: Beam Model Calculation

EC2�

wor

ked

exam

ples

2-11

Tabl

eof

Cont

ent

four

thco

mbi

natio

n

1.35

·Sk,

terr

+1.

35·G

k,w

all+

1.0·

Gk,

terr

+1.

5·Q

k,so

vr+

1.5·

S k,so

vr

the

cont

act

pres

sure

ongr

ound

isca

lcul

ated

,for

the

first

ofth

efo

urth

abov

e-m

entio

ned

com

bina

tions

,asf

ollo

ws:

mom

entv

s.cen

treof

mass

ofth

efoo

ting

mom

entf

rom

grou

ndla

tera

lfor

ce(

G=

1.35

):M

S,te

rr=

1.35

(26.

733.

00/3

)=36

.08

kNm

/mm

omen

tfro

msu

rcha

rge

late

ralf

orce

(Q=

1.5)

:M

S,so

vr=

1.5

(9.9

01.

50)=

22.2

8kN

m/m

mom

entf

rom

wall

self-

weig

ht(

G=

1.0)

:M

wall

=1.

0(1

8.75

0.60

)=11

.25

kNm

/mm

omen

tfro

mfo

otin

gse

lf-w

eigh

t(G=

1.0)

:M

foot

=0

kNm

/mm

omen

tfro

mgr

ound

self-

wei

ght(

G=

1.0)

:M

grou

nd=

-1.0

(76.

50.

40)=

-30.

6kN

m/m

Tota

lmom

entM

tot=

36.0

8+

22.2

8+

11.2

5�

30.6

=39

.01

kNm

/m

Vert

icall

oad

Wall

self-

wei

ght(

G=

1.0)

:P w

all=

1.0

(18.

75)=

18.7

5kN

m/m

Foot

ing

self-

wei

ght(

G=

1.0)

:P f

oot=

1.0

(31.

25)=

31.2

5kN

m/m

Gro

und

self-

weig

ht(

G=

1.0)

:P g

roun

d=

1.0

(76.

5)=

76.5

kNm

/mTo

tall

oad

P tot

=18

.75

+31

.25

+76

.5=

126.

5kN

/mE

ccen

trici

tye

=M

tot/

P tot

=39

.01

/12

6.5

=0.

31m

B/6

=2.

50/6

=41

.67

cmM

axpr

essu

reon

grou

nd=

P tot

/2.

50+

Mto

t6

/2.

502

=88

.05

kN/m

2=

0.08

8M

Pa

The

resu

ltsgi

ven

atTa

ble

2.2

are

obta

ined

byre

peat

ing

the

calc

ulat

ion

fort

heth

ree

rem

aini

ngco

mbi

natio

nsof

parti

alfa

ctor

s.Th

em

axim

alpr

essu

reon

grou

ndis

achi

eved

with

the

seco

ndco

mbi

natio

n,i.e

.for

the

one

inw

hich

the

wall

self-

weigh

tand

thes

elf-w

eight

ofth

egro

und

abov

ethe

foot

ing

areb

oth

mul

tiplie

dby

1.35.

For

the

verif

icatio

nof

the

cont

act

pres

sure

,the

poss

ibilit

yth

atth

esu

rcha

rge

acts

onth

ewh

ole

emba

nkm

ent

surfa

cem

ust

beals

oco

nsid

ered

.(F

ig.

2.13

);th

eva

lues

give

nat

Tabl

e2.

3ar

eob

tain

edby

repe

atin

gth

eca

lcula

tion

fort

hiss

ituat

ion.

Fig.

2.13

.Dim

ensio

nsof

ther

etain

ingw

allo

fthe

num

erice

xam

plewi

thsu

rchar

geon

thew

hole

emba

nkm

ent.

EC2�

wor

ked

exam

ples

2-12

Tabl

eof

Cont

entT

able

2.2.

Max

press

uref

orfou

rdiff

erent

combi

natio

nsof

parti

alfac

torso

fperm

anen

tloa

ds(su

rchar

geou

tside

thef

ound

ation

footin

g).Co

mbin

ation

first

seco

ndth

irdfo

urth

MS,

groun

d(k

Nm/

m)

36.0

8(

Q=

1.35

)36

.08

(Q=

1.35

)36

.08

(Q

=1.

35)

36.0

8(

Q=

1.35

)M

S,su

rch(k

Nm/

m)

22.2

8(

Q=

1.5)

22.2

8(

Q=

1.5)

22.2

8(

Q=

1.5)

22.2

8(

Q=

1.5)

Mwa

ll(k

Nm/

m)

11.2

5(

G=

1.0)

15.1

9(

G=

1.35

)11

.25

(G

=1.

0)15

.19

(G=

1.35

)M

groun

d(k

Nm/

m)

-30.

60(

G=

1.0)

-41.

31(

G=

1.35

)-4

1.31

(G

=1.

35)

-30.

60(

G=

1.0)

Mtot

(kN

m/m

)39

.01

32.2

428

.30

42.9

5

P wall

(kN

/m)

18.7

5(

G=

1.0)

25.3

1(

G=

1.35

)18

.75

(G

=1.

0)25

.31

(G

=1.

35)

P foo

t(k

N/m

)31

.25

(G

=1.

0)42

.19

(G=

1.35

)31

.25

(G

=1.

0)42

.19

(G

=1.

35)

P gro

und

(kN

/m)

76.5

0(

G=

1.0)

103.

28(

G=

1.35

)10

3.28

(G

=1.

35)

76.5

0(

G=

1.0)

P tot

(kN

/m)

126.

5017

0.78

153.

2814

4

eccen

tricit

y(m)

0.31

0.19

0.18

0.30

press

ureo

ngr

ound

(kN

/m2 )

88.0

599

.26

88.4

898

.83

Tab

le2.

3.M

axpr

essur

eon

groun

dfor

fourd

iffere

ntcom

binat

ionso

fpar

tialf

actor

sofp

erman

entl

oads

(surch

arge

onth

ewho

lefou

ndat

ionfoo

ting).

Com

binat

ionfir

stse

cond

third

four

thM

S,gro

und

(kN

m/m

)36

.08

(Q=

1.35

)36

.08

(Q

=1.

35)

36.0

8(

Q=

1.35

)36

.08

(Q=

1.35

)M

S,su

rch(k

Nm/

m)

22.2

8(

Q=

1.5)

22.2

8(

Q=

1.5)

22.2

8(

Q=

1.5)

22.2

8(

Q=

1.5)

Mwa

ll(k

Nm/

m)

11.2

5(

G=

1.0)

15.1

9(

G=

1.35

)11

.25

(G=

1.0)

15.1

9(

G=

1.35

)M

groun

d(k

Nm/

m)

-30.

60(

G=

1.0)

-41.

31(

G=

1.35

)-4

1.31

(G=

1.35

)-3

0.60

(G=

1.0)

Msu

rch

(kN

m/m

)-1

0.20

(Q

=1.

5)-1

0.20

(Q=

1.5)

-10.

20(

Q=

1.5)

-10.

20(

Q=

1.5)

Mtot

(kN

m/m

)28

.81

22.0

418

.10

32.7

5

P wall

(kN

/m)

18.7

5(

G=

1.0)

25.3

1(

G=

1.35

)18

.75

(G=

1.0)

25.3

1(

G=

1.35

)P f

oot

(kN

/m)

31.2

5(

G=

1.0)

42.1

9(

G=

1.35

)31

.25

(G=

1.0)

42.1

9(

G=

1.35

)P t

err(k

N/m

)76

.50

(G

=1.

0)10

3.28

(G

=1.

35)

103.

28(

G=

1.35

)76

.50

(G=

1.0)

Psur

ch(k

N/m

)25

.50

(Q

=1.

5)25

.50

(Q

=1.

5)25

.50

(Q

=1.

5)25

.50

(Q=

1.5)

P tot

(kN

/m)

152.

019

6.28

178.

7816

9.50

eccen

tricit

y(m)

0.19

0.11

0.10

0.19

press

ureo

ngr

ound

(kN

/m2 )

88.4

699

.67

88.8

999

.24

The

two

addi

tiona

llin

es,n

otpr

esen

tin

Tabl

e1.

18an

dhe

rehi

ghlig

hted

inbo

ld,c

orre

spon

dto

the

mom

enta

ndto

the

verti

cal

load

resu

lting

from

the

surc

harg

eabo

veth

efo

otin

g.

The

max

pres

sure

ongr

ound

isac

hiev

edon

ceag

ainfo

rthe

seco

ndco

mbi

natio

nan

dits

valu

eis

here

high

erth

anth

eon

eca

lculat

edin

the

prev

ious

sche

me.

Page 12: Beam Model Calculation

EC2�

wor

ked

exam

ples

4-1

Tabl

eof

Cont

ent

SEC

TIO

N4.

WO

RK

ED

EX

AM

PLE

S–

DU

RA

BIL

ITY

EX

AM

PL

E4.

1[E

C2

clau

se4.

4]

Des

ign

the

conc

rete

cove

rofa

rein

forc

edco

ncre

tebe

amw

ithex

posu

recl

assX

C1.

The

conc

rete

inus

eha

sres

ista

nce

clas

sC

25/3

0.B

otto

mlo

ngitu

dina

lbar

sare

520

;the

stirr

upsa

re8

at10

0m

m.

The

max

aggr

egat

esi

zeis

:dg

=20

mm

(<32

mm

).Th

ede

sign

wor

king

life

ofth

est

ruct

ure

is50

year

s.N

orm

alqu

ality

cont

roli

sput

inpl

ace.

Ref

erto

figur

e4.

1.

Fig.

4.1

From

tabl

eE.

1N-E

C2

we

see

that

,in

orde

rto

obta

inan

adeq

uate

conc

rete

dura

bilit

y,th

ere

fere

nce

(min

.)co

ncre

test

reng

thcl

ass

for

expo

sure

clas

sX

C1

isC

20/2

5;th

ere

sist

ance

clas

sado

pted

(C25

/30)

issu

itabl

eas

itis

high

erth

anth

ere

fere

nce

stre

ngth

clas

s.

The

stru

ctur

alcl

assi

sS4.

Firs

t,th

eco

ncre

teco

verf

orth

est

irrup

sis

calc

ulat

ed.

With

:c m

in,b

=8

mm

We

obta

infr

omta

ble

4.4N

-EC

2:c m

in,d

ur=

15m

m

Mor

eove

r:c d

ur,

=0

;c d

ur,st

=0

;c d

ur,a

dd=

0.

From

rela

tion

(3.2

):c m

in=

max

(cm

in,b

;cm

in,d

ur+

c dur

,-

c dur

,st-

c dur

,add

;10

mm

)=m

ax(8

;15

+0�

0�

0;10

mm

)=15

mm

EC2�

Wor

ked

exam

ples

4-2

Tabl

eof

Cont

ent

Mor

eove

r:de

vc

=10

mm

.

We

obta

infr

omre

latio

n(3

.1):

nom

min

dev

cc

c=

15+

10=

25m

m.

Ifw

eno

wca

lcul

ate

now

the

conc

rete

cove

rfor

long

itudi

nalr

einf

orce

men

tbar

s,

we

have

:m

in,b

c=

20m

m.

We

obta

infr

omta

ble

4.4N

-EC

2:m

in,d

urc

=15

mm

.

Mor

eove

r:du

r,c

=0

;

dur,s

tc

=0

;

dur,a

ddc

=0

.

From

rela

tion

(3.2

):m

inc

=m

ax(2

0;15

+0�

0�

0;10

mm

)=20

mm

.

Mor

eove

r:de

vc

=10

mm

.

We

obta

infr

omre

latio

n(3

.1):

nom

c=

20+

10=

30m

m.

The

conc

rete

cove

rfo

rth

est

irrup

sis�d

omin

ant�

.In

this

case

,th

eco

ncre

teco

ver

for

long

itudi

nalb

arsi

sinc

reas

edto

:25

+8

=33

mm

.

Page 13: Beam Model Calculation

EC2�

wor

ked

exam

ples

4-3

Tabl

eof

Cont

ent

EX

AM

PL

E4.

2[E

C2

clau

se4.

4]

Des

ign

the

conc

rete

cove

rfo

ra

rein

forc

edco

ncre

tebe

ampl

aced

outs

ide

are

side

ntia

lbu

ildin

gsi

tuat

edcl

ose

toth

eco

ast.

The

expo

sure

clas

sisX

S1.

We

orig

inal

lyas

sum

eco

ncre

tew

ithst

reng

thcl

assC

25/3

0.Th

elo

ngitu

dina

lrei

nfor

cem

entb

ars

are

520

;the

stirr

upsa

re8

at10

0m

m.

The

max

imal

aggr

egat

esi

zeis

:dg

=20

mm

(<32

mm

).Th

ede

sign

wor

king

life

ofth

est

ruct

ure

is50

year

s.A

norm

alqu

ality

cont

roli

spu

tin

plac

e.R

efer

tofig

ure

3.2.

From

tabl

eE.

1N-E

C2

we

find

that

,in

orde

rto

obta

inan

adeq

uate

conc

rete

dura

bilit

y,th

ere

fere

nce

(min

.)co

ncre

test

reng

thcl

ass

for

expo

sure

clas

sX

S1is

C30

/37;

the

conc

rete

stre

ngth

clas

sm

ustt

here

fore

bein

crea

sed

from

the

orig

inal

lyas

sum

edC

25/3

0to

C30

/37,

even

ifth

eac

tions

onco

ncre

tew

ere

com

patib

lew

ithst

reng

thcl

assC

25/3

0.

Fig.

4.2

Inac

cord

ance

with

wha

thas

been

stat

edin

exam

ple

3.1,

we

desi

gnth

em

inim

umco

ncre

teco

verw

ithre

fere

nce

tobo

thth

est

irrup

sand

the

long

itudi

nalb

ars.

The

stru

ctur

alcl

assi

sS4

We

obta

in(

min

,dur

c=

35m

m;

dev

c=

10m

m):

-fo

rthe

stirr

ups:

nom

c=

45m

m;

-fo

rthe

long

itudi

nalb

ars:

nom

c=

45m

m.

The

conc

rete

cove

rfo

rth

est

irrup

sis�d

omin

ant�

.In

this

case

,th

eco

ncre

teco

ver

for

long

itudi

nalb

arsi

sinc

reas

edto

:45

+8

=53

mm

.

EC2�

Wor

ked

exam

ples

4-4

Tabl

eof

Cont

ent

EX

AM

PL

E4.

3[E

C2

clau

se4.

4]

Calc

ulat

eth

eco

ncre

teco

vero

faTT

prec

aste

lem

ent,

mad

eof

pres

tress

edre

info

rced

conc

rete

,pl

aced

outsi

dean

indu

stria

lbui

ldin

gsit

uate

dcl

oset

oth

ecoa

st.

Thee

xpos

ure

clas

sisX

S1.

We

use

conc

rete

with

stre

ngth

clas

sC

45/5

5.A

tthe

low

ersi

deof

the

two

ribbi

ngs

ofth

eTT

elem

entw

eha

ve:

long

itudi

nal

12re

info

rcem

entb

ars;

8st

irrup

sat

100

mm

;st

rand

s0,

5�.

The

max

imal

aggr

egat

esi

zeis

:dg

=16

mm

.Th

ede

sign

wor

king

life

ofth

est

ruct

ure

is50

year

s.A

nac

cura

tequ

ality

cont

rolo

fcon

cret

epr

oduc

tion

ispu

tin

plac

e.R

efer

tofig

ure

3.3.

We

find

out

from

tabl

eE.

1N-

EC2

that

for

expo

sure

clas

sX

S1,t

hem

inim

umco

ncre

test

reng

thcl

assi

sC30

/37;

stre

ngth

clas

sC

45/5

5is

ther

efor

ead

equa

te.

The

orig

inal

stru

ctur

alcl

assi

sS4

.In

acco

rdan

cew

ithta

ble

4.3N

:th

est

ruct

ural

clas

sis

redu

ced

by1

asth

eco

ncre

teus

ed(C

45/5

5)is

ofst

reng

thcl

ass

high

erth

anC

40/5

0;th

est

ruct

ural

clas

sis

redu

ced

by1

assp

ecia

lqua

lity

cont

rolo

fthe

conc

rete

prod

uctio

nis

ensu

red

We

then

refe

rto

stru

ctur

alcl

ass

S2.

Cal

cula

ting

first

the

conc

rete

cove

rfor

stirr

ups.

We

have

:m

in,b

c=

8m

m.

We

obta

infr

omta

ble

4.4N

-EC

2:m

in,d

urc

=25

mm

.

Mor

eove

r:du

r,c

=0

;

dur,s

tc

=0

;

dur,a

ddc

=0

.

From

rela

tion

(3.2

):m

inm

in,b

min

,dur

dur,

dur,

stdu

r,ad

dc

max

(c;

cc

cc

;10

mm

)=

=m

ax(8

;25

+0�

0�

0;10

mm

)=25

mm

.

Page 14: Beam Model Calculation

EC2�

wor

ked

exam

ples

4-5

Tabl

eof

Cont

ent

Con

side

ring

that

the

TTel

emen

tis

cast

unde

rpr

oced

ures

subj

ecte

dto

ahi

ghly

effic

ient

qual

ityco

ntro

l,in

whi

chth

eco

ncre

teco

verl

engt

his

also

asse

ssed

,the

valu

eof

c dev

can

beta

ken

as5

mm

.

We

obta

infr

omre

latio

n(3

.1):

nom

min

dev

cc

c=

25+

5=

30m

m.

Cal

cula

ting

now

the

conc

rete

cove

rfor

long

itudi

nalb

ars.

We

have

:m

in,b

c=

12m

m.

We

obta

infr

omta

ble

4.4N

-EC

2:m

in,d

urc

=25

mm

.

Mor

eove

r:du

r,c

=0

;

dur,s

tc

=0

;

dur,a

ddc

=0

.

From

rela

tion

(3.2

):m

inm

in,b

min

,dur

dur,

dur,

stdu

r,ad

dc

max

(c;

cc

cc

;10

mm

)=

=m

ax(1

2;25

+0�

0�

0;10

mm

)=25

mm

.

We

obta

infr

omre

latio

n(3

.1):

nom

min

dev

cc

c=

25+

5=

30m

m.

Not

eth

atfo

rthe

ordi

nary

rein

forc

emen

tbar

s,th

eco

ncre

teco

verf

orst

irrup

sis�d

omin

ant�

.In

this

case

,the

conc

rete

cove

rfor

long

itudi

nalb

arsi

sin

crea

sed

to:3

0+

8=

38m

m.

Fig.

4.3

Cal

cula

ting

now

the

conc

rete

cove

rfor

stra

nds.

EC2�

Wor

ked

exam

ples

4-6

Tabl

eof

Cont

ent

We

have

:m

in,b

c=

1,5

·12,

5=

18,8

mm

.

We

obta

infr

omta

ble

4.5N

-EC

2:m

in,d

urc

=35

mm

.

Mor

eove

r:du

r,c

=0

;

dur,s

tc

=0

;

dur,a

ddc

=0

.

From

rela

tion

(3.2

):m

inc

=m

ax(1

8,8;

35+

0�

0�

0;10

mm

)=35

mm

.

Mor

eove

r:de

vc

=5

mm

.

From

rela

tion

(3.1

):no

mc

=35

+5

=40

mm

.

The

first

stra

nd�s

axis

ispl

aced

at50

mm

from

the

low

eren

dof

the

ribbi

ngof

the

TTel

emen

t.Th

eco

ncre

teco

verf

orth

elo

wer

stra

nds

ofth

eTT

elem

ent(

one

fore

ach

ribbi

ng)

isth

eref

ore

equa

lto

43m

m.

Page 15: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-1

6-1

SEC

TIO

N6.

WO

RK

ED

EX

AM

PLE

S–

ULT

IMAT

EL

IMIT

STAT

ES

GE

NE

RA

LN

OT

E:Eu

roco

de2

perm

itsto

use

ava

rious

stee

lyi

eldi

nggr

ades

rang

ing

from

400

MPa

to60

0M

Pa.I

npa

rticu

lart

heex

ampl

esar

ede

velo

ped

usin

gS4

50st

eelw

ithdu

ctili

tygr

ade

C,w

hich

isus

edin

sout

hern

Euro

pean

dge

nera

llyin

seis

mic

area

s.So

me

exam

ple

isde

velo

ped

usin

gS5

00to

o.

EX

AM

PL

E6.

1(C

oncr

ete

C30

/37)

[EC

2cl

ause

6.1]

Geo

met

rical

data

:b=

500

mm

;h=

1000

mm

;d'=

50m

m;d

=95

0m

m.

Stee

land

conc

rete

resi

stan

ce,

1an

d2

fact

orsa

ndx 1

,x2

valu

esar

esh

own

inta

ble

6.1.

Bas

is:

1m

eans

the

ratio

betw

een

the

area

ofth

epa

rabo

la�

rect

angl

edi

agra

mat

certa

inde

form

atio

nc

and

the

area

ofre

ctan

gle

atth

esa

me

defo

rmat

ion.

2is

the�p

ositi

onfa

ctor�,

the

ratio

betw

een

the

dist

ance

ofth

ere

sulta

ntof

para

bola

�re

ctan

gle

diag

ram

atce

rtain

defo

rmat

ion

cfr

omc

and

the

defo

rmat

ion

cits

elf.

Fig

.6.1

Geo

met

rica

ldat

aan

dPo

ssib

lestr

ain

distr

ibut

ions

atth

eul

timat

elim

itsta

tes

Tabl

e6.

1M

ater

iald

ata,

1an

d2

fact

orsa

ndne

utra

laxi

sdep

th.

Exam

ple

f yk(M

Pa)

f yd(M

Pa)

f ck(M

Pa)

f cd(M

Pa)

12

x 1(m

m)

x 2(m

m)

6.1

450

391

3017

0.80

0.40

113,

560

8,0

6.2

450

391

9051

0.56

0.35

203.

054

1.5

Firs

tth

eN

Rd

valu

esco

rres

pond

ing

toth

e4

conf

igur

atio

nsof

the

plan

ese

ctio

nar

eca

lcul

ated

.

NR

d1=

0.8·

500·

113.

5·17

·10-3

=77

2kN

NR

d2=

0.8·

500·

608.

0·17

·10-3

=41

34kN

.

The

max

imum

mom

entr

esis

tanc

eM

Rd,

max

=28

21.2

kNm

goes

alon

gsid

eit.

NR

d3=

0.8·

500·

950·

17·1

0-3+

5000

·391

·10-3

=64

60+

1955

=84

15kN

NR

d4=

0.8·

500·

1000

·17·

10-3

+50

00·3

91·1

0-3=

8500

+39

10=

1241

0kN

EC2�

wor

ked

exam

ples

6-2

Tabl

eof

Cont

ent

MR

d3m

usta

lso

bekn

own.

This

resu

lts:M

Rd3

=64

60·(5

00�

0,4·

950)

·10-3

=16

55kN

m

Subs

eque

ntly

,for

ach

osen

valu

eof

NEd

inea

chin

terv

albe

twee

ntw

ofo

llow

ing

valu

esof

NR

dw

ritte

nab

ove

and

one

smal

lert

han

NR

d1,t

hene

utra

laxi

sx,M

Rd,

and

the

ecce

ntric

ity

e=

Rd Ed

M Nar

eca

lcul

ated

.The

irva

lues

are

show

nin

Tabl

e6.

2.

Tabl

e6.2

.Exa

mpl

e1:v

alue

sofa

xial

forc

e,de

pth

ofne

utra

laxis

,mom

entr

esist

ance

,ecc

entri

city.

NEd

(kN

)X

(m)

MR

d(k

Nm

)e

(m)

600

0,10

520

313.

3820

000,

294

2524

1.26

5000

0,66

626

060.

5210

000

virtu

alne

utra

laxi

s10

000.

10

As

anex

ampl

eth

eca

lcul

atio

nre

late

dto

NEd

=50

00kN

issh

own.

The

equa

tion

ofeq

uilib

rium

tosh

iftin

gfo

rdet

erm

inat

ion

ofx

isw

ritte

n:

250

0000

050

0039

150

000.

0035

2000

0050

000.

0035

2000

0050

0095

0x

x0

0.80

500

170.

8050

017

Dev

elop

ing,

itre

sults

:

x2+

66.9

1x�

4889

70=

0

whi

chis

satis

fied

forx

=66

6m

m

The

stre

ssin

the

low

erre

info

rcem

enti

s:2

s95

00.

0035

2000

001

297N

/m

m66

6

The

mom

entr

esis

tanc

eis

:

MR

d=

5000

·391

·(500

-50)

+50

00·2

97·(5

00-5

0)+

0.80

·666

·500

·17·

(500

�0.

4066

6)=

2606

·106

Nm

m=

2606

kNm

and

the

ecce

ntric

ity26

06e

0,52

m50

00

Page 16: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-3

Tabl

eof

Cont

ent

EX

AM

PL

E6.

2(C

oncr

ete

C90

/105

)[E

C2

clau

se6.

1]

Forg

eom

etric

alan

dm

echa

nica

ldat

are

fert

oex

ampl

e6.

1.

Val

ueso

fNR

dco

rres

pond

ing

toth

e4

conf

igur

atio

nsof

the

plan

ese

ctio

nan

dof

MR

d3:

NR

d1=

2899

kN

NR

d2=

7732

kN.

MR

d,m

ax=

6948

.7kN

mis

asso

ciat

edto

it.

NR

d3=

1356

6+

3910

=17

476

kN

NR

d4=

1428

0+

7820

=22

100

kN

MR

d3=

1356

6(0

.5�

0.35

·0.6

19)+

3910

·(0.5

0-0.

05)=

4031

kNm

App

lyin

gth

eex

plai

ned

proc

edur

ex,

MR

dan

dth

eec

cent

ricity

ew

ere

calc

ulat

edfo

rth

ech

osen

valu

esof

NEd

.

The

resu

ltsar

esh

own

inTa

ble

6.3

Tabl

e6.

3Va

lues

ofax

iall

oad,

dept

hof

neut

rala

xis,

mom

entr

esis

tanc

e,ec

cent

ricity

NEd

(kN

)x (m

)M

Rd(k

Nm

)e (m

)15

000,

142

4194

2.80

5000

0,35

054

031.

0810

000

0,61

955

140.

5519

000

virtu

alne

utra

laxi

s27

020.

14

EC2�

wor

ked

exam

ples

6-4

Tabl

eof

Cont

ent

EX

AM

PL

E6.

3C

alcu

latio

nof

VR

d,c

fora

pres

tres

sed

beam

[EC

2cl

ause

6.2]

Rec

tang

ular

sect

ion

b w=

100

mm

,h=

200

mm

,d=

175

mm

.No

long

itudi

nalo

rtra

nsve

rse

rein

forc

emen

tbar

sare

pres

ent.

Cla

ssC

40co

ncre

te.

Ave

rage

pres

tress

ing

cp=

5,0

MPa

.

Des

ign

tens

ilere

sist

ance

inac

cord

ance

with

:

f ctd

=ct

f ctk,

0,05

/C

=1·

2,5/

1,5=

1,66

MPa

Cra

cked

sect

ions

subj

ecte

dto

bend

ing

mom

ent.

VR

d,c=

(m

in+

k 1cp

)bwd

whe

rem

in=

0,62

6an

dk 1

=0,

15.I

tres

ults

:

VR

d,c=

(0.6

26+

0.15

5.0)

100

175

=24

.08

kN

Non

-cra

cked

sect

ions

subj

ecte

dto

bend

ing

mom

ent.

With

I=

1it

resu

lts

I=3

64

200

100

66.6

610

mm

12

S=

33

100

100

5050

010

mm

VR

d,c=

62

3

100

66.6

610

1.66

1,66

5.0

44.3

3kN

500

10

Page 17: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-5

Tabl

eof

Cont

ent

EX

AM

PL

E6.

4D

eter

min

atio

nof

shea

rre

sist

ance

give

nth

ese

ctio

nge

omet

ryan

dm

echa

nics

[EC

2cl

ause

6.2]

Rec

tang

ular

orT-

shap

edbe

am,w

ith

b w=

150

mm

,

h=

600

mm

,

d=

550

mm

,

z=

500

mm

;

verti

cals

tirru

psdi

amet

er12

mm

,2le

gs(A

sw=

226

mm

2 ),s=

150

mm

,fyd

=39

1M

Pa.

The

exam

ple

isde

velo

ped

fort

hree

clas

seso

fcon

cret

e.

a)f ck

=30

MPa

;fcd

=17

MPa

;=

0.61

6

swyw

d2

wcd

Af

sinb

sf

obta

ined

from

VR

d,s=

VR

d,m

ax

itre

sults

:2

226

391

sin0.

375

150

150

0.61

617

henc

eco

t=

1,29

Then

3sw

Rd,s

ywd

A22

6V

zf

cot

500

391

1.29

1038

0kN

s15

0

b)Fo

rthe

sam

ese

ctio

nan

dre

info

rcem

ent,

with

f ck=

60M

Pa,f

cd=

34M

Pa;

=0.

532,

proc

eedi

ngas

abov

eit

resu

lts:

222

639

1sin

0.21

7115

015

00.

532

34he

nce

cot

=1,

90

3sw

Rd,s

ywd

A22

6V

zf

cot

500

391

1.90

1056

0kN

s15

0

c)Fo

rth

esa

me

sect

ion

and

rein

forc

emen

t,w

ithf ck

=90

MPa

,fcd

=51

MPa

;=

0.51

2,pr

ocee

ding

asab

ove

itre

sults

:

222

639

1sin

0.15

0415

015

00.

512

51he

nce

cot

=2.

38

3sw

Rd,s

ywd

A22

6V

zf

cot

500

391

2.38

1070

1kN

s15

0

EC2�

wor

ked

exam

ples

6-6

Tabl

eof

Cont

ent

Det

erm

inat

ion

ofre

info

rcem

ent(

vert

ical

stir

rups

)giv

enth

ebe

aman

dsh

ear

actio

nV

Ed

Rec

tang

ular

beam

b w=

200

mm

,h=

800

mm

,d

=75

0m

m,z

=67

5m

m;v

ertic

alst

irrup

sf y

wd

=39

1M

Pa.T

hree

case

sare

show

n,w

ithva

ryin

gva

lues

ofV

Edan

dof

f ck.

VEd

=60

0kN

;fck

=30

MPa

;fcd

=17

MPa

;=

0.61

6

Then

oE

d

cwcd

w

2V1

12

6000

00ar

csin

arcs

in29

.02

(f

)bz

2(1

0.61

617

)20

067

5

henc

eco

t=

1.80

Itre

sults

:2

swE

d

ywd

AV

6000

001.

263

mm

/m

ms

zf

cot

675

391

1.80

whi

chis

satis

fied

with

2-le

gst

irrup

s12

/170

mm

.

The

tens

ilefo

rce

inth

ete

nsio

ned

long

itudi

nal

rein

forc

emen

tne

cess

ary

for

bend

ing

mus

tbe

incr

ease

dby

F td

=0.

5V

Edco

t=

0.5·

6000

00·1

.80

=54

0kN

VEd

=90

0kN

;fck

=60

MPa

;fcd

=34

MPa

;=

0.53

2

oE

d

cwcd

w

2V1

12

9000

00ar

csin

arcs

in23

.74

2(

f)b

z2

(10.

532

34)

200

675

henc

eco

t=

2.27

Then

with

itre

sults

2sw

Ed

ywd

AV

9000

001.

50m

m/

mm

sz

fco

t67

539

12.

27

whi

chis

satis

fied

with

2-le

gst

irrup

s12

/150

mm

.

The

tens

ilefo

rce

inth

ete

nsio

ned

long

itudi

nal

rein

forc

emen

tne

cess

ary

for

bend

ing

mus

tbe

incr

ease

dby

F td

=0.

5V

Edco

t=

0.5·

9000

00·2

.27=

1021

kN

VEd

=12

00kN

;fck

=90

MPa

;fcd

=51

MPa

;=

0.51

2

oE

d

cwcd

w

2V1

12

1200

000

arcs

inar

csin

21.4

52

(f

)bz

20.

512

5120

067

5

As

issm

alle

rtha

n21

.8o

,cot

=2.

50

Hen

ce2

swE

d

ywd

AV

1200

000

1.82

mm

/m

ms

zf

cot

675

391

2.50

whi

chis

satis

fied

with

2-le

gst

irrup

s12

/120

mm

.

The

tens

ilefo

rce

inth

ete

nsio

ned

long

itudi

nal

rein

forc

emen

tne

cess

ary

for

bend

ing

mus

tbe

incr

ease

dby

F td

=0.

5V

Edco

t=

0.5·

1200

000·

2.50

=15

00kN

Page 18: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-7

Tabl

eof

Cont

ent

EX

AM

PL

E6.

4b�

the

sam

eab

ove,

with

stee

lS50

0Cf yd

=43

5M

Pa.

[EC

2cl

ause

6.2]

The

exam

ple

isde

velo

ped

fort

hree

clas

seso

fcon

cret

e.

a)f ck

=30

MPa

;fcd

=17

MPa

;=

0.61

6

swyw

d2

wcd

Af

sinb

sf

obta

ined

forV

Rd,

s=V

Rd,

max

itre

sults

:2

226

435

sin0.

417

150

150

0.61

617

henc

eco

t=

1.18

Then

3sw

Rd,s

ywd

A22

6V

zf

cot

500

435

1.18

1038

7kN

s15

0

b)Fo

rthe

sam

ese

ctio

nan

dre

info

rcem

ent,

with

f ck=

60M

Pa,f

cd=

34M

Pa;

=0.

532,

proc

eedi

ngas

abov

eit

resu

lts:

222

643

5sin

0.24

215

015

00.

532

34he

nce

cot

=1.

77

3sw

Rd,s

ywd

A22

6V

zf

cot

500

435

1.77

1058

0kN

s15

0

c)Fo

rth

esa

me

sect

ion

and

rein

forc

emen

t,w

ithf ck

=90

MPa

,fcd

=51

MPa

;=

0.51

2,pr

ocee

ding

asab

ove

itre

sults

:

222

643

5sin

0.16

715

015

00.

512

51he

nce

cot

=2.

23

3sw

Rd,s

ywd

A22

6V

zf

cot

500

435

2.23

1073

1kN

s15

0

Det

erm

inat

ion

ofre

info

rcem

ent(

vert

ical

stir

rups

)giv

enth

ebe

aman

dsh

ear

actio

nV

Ed

Rec

tang

ular

beam

b w=

200

mm

,h=

800

mm

,d

=75

0m

m,z

=67

5m

m;v

ertic

alst

irrup

sf y

wd

=39

1M

Pa.T

hree

case

sare

show

n,w

ithva

ryin

gva

lues

ofV

Edan

dof

f ck.

VEd

=60

0kN

;fck

=30

MPa

;fcd

=17

MPa

;=

0.61

6th

en

oE

d

cwcd

w

2V1

12

6000

00ar

csin

arcs

in29

.02

(f

)bz

2(1

0.61

617

)20

067

5he

nce

cot

=1.

80

Itre

sults

:2

swE

d

ywd

AV

6000

001.

135

mm

/m

ms

zf

cot

675

435

1.80

whi

chis

satis

fied

with

2-le

gst

irrup

s12

/190

mm

.

The

tens

ilefo

rce

inth

ete

nsio

ned

long

itudi

nal

rein

forc

emen

tnec

essa

ryfo

rbe

ndin

gm

ust

bein

crea

sed

byF t

d=

0.5

VEd

cot

=0.

5·60

0000

·1.8

0=

540

kN

EC2�

wor

ked

exam

ples

6-8

Tabl

eof

Cont

ent

VEd

=90

0kN

;fck

=60

MPa

;fcd

=34

MPa

;=

0.53

2

oE

d

cwcd

w

2V1

12

9000

00ar

csin

arcs

in23

.74

2(

f)b

z2

(10.

532

34)

200

675

henc

eco

t=

2.27

Then

with

itre

sults

2sw

Ed

ywd

AV

9000

001.

35m

m/

mm

sz

fco

t67

543

52.

27

whi

chis

satis

fied

with

2-le

gst

irrup

s12

/160

mm

.

The

tens

ilefo

rce

inth

ete

nsio

ned

long

itudi

nal

rein

forc

emen

tne

cess

ary

for

bend

ing

mus

tbe

incr

ease

dby

F td

=0.

5V

Edco

t=

0.5·

9000

00·2

.27

=10

21kN

VEd

=12

00kN

;fck

=90

MPa

;fcd

=51

MPa

;=

0.51

2

oE

d

cwcd

w

2V1

12

1200

000

arcs

inar

csin

21.4

52

(f

)bz

20.

512

5120

067

5

As

issm

alle

rtha

n21

.8o

,cot

=2.

50

Hen

ce2

swE

d

ywd

AV

1200

000

1.63

mm

/m

ms

zf

cot

675

435

2.50

whi

chis

satis

fied

with

2-le

gst

irrup

s12

/130

mm

.

The

tens

ilefo

rce

inth

ete

nsio

ned

long

itudi

nal

rein

forc

emen

tne

cess

ary

for

bend

ing

mus

tbe

incr

ease

dby

F td

=0.

5V

Edco

t=

0.5·

1200

000·

2.50

=15

00kN

Page 19: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-9

Tabl

eof

Cont

ent

EX

AM

PL

E6.

5[E

C2

clau

se6.

2]

Rec

tang

ular

orT-

shap

edbe

am,w

ith

b w=

150

mm

h=

800

mm

d=

750

mm

z=

675

mm

;

f ck=

30M

Pa;f

cd=

17M

Pa;

=0.

616

Rei

nfor

cem

ent:

incl

ined

stirr

ups

45o

(cot

=1,

0),d

iam

eter

10m

m,2

legs

(Asw

=15

7m

m2 ),

s=

150

mm

,f y

d=

391

MPa

.

Cal

cula

tion

ofsh

earr

esis

tanc

e

Duc

tility

isfir

stve

rifie

dby

sw,m

axyw

dcw

1cd

w

Af

f0.

5b

ssin

And

repl

acin

g15

739

11

0.61

617

0.5

150

150

0.70

7=

2.72

<7.

40

The

angl

eof

sim

ulta

neou

scon

cret

e�

rein

forc

emen

tste

elco

llaps

e

Itre

sults

cd

swyw

d

bsf

cot

1A

fsin

and,

repl

acin

g15

015

00.

616

17co

t1

2.10

157

391

0.70

7

c)C

alcu

latio

nof

VR

d

Itre

sults

:3

Rd,s

157

V67

539

1(2

.10

1.0)

0.70

710

605.

4kN

150

Incr

ease

ofte

nsile

forc

eth

elo

ngitu

dina

lbar

(VEd

=VR

d,s)

F td

=0.

5V

Rd,

s(c

otco

t=

0.5·

605.

4·(2

.10

-1.0

)=33

3kN

EC2�

wor

ked

exam

ples

6-10

Tabl

eof

Cont

ent

EX

AM

PL

E6.

6[E

C2

clau

se6.

3]

Rin

gre

ctan

gula

rse

ctio

n,Fi

g.6.

2,w

ithde

pth

1500

mm

,wid

th10

00m

m,d

=14

50m

m,

with

200

mm

wid

eve

rtica

lmem

bers

and

150

mm

wid

eho

rizon

talm

embe

rs.

Mat

eria

ls:

f ck=

30M

Pa

f yk

=50

0M

Pa

Res

ults

ofac

tions

:

VEd

=13

00kN

(for

cepa

ralle

lto

the

larg

ersi

de)

T Ed=

700

kNm

Des

ign

resi

stan

ces:

f cd=0

.85·

(30/

1.5)

=17

.0M

Pa

=0.

7[1-

30/2

50]=

0.61

6

f cd=

10.5

MPa

f yd

=50

0/1.

15=

435

MPa

Geo

met

ricel

emen

ts:

u k=

2(15

00-1

50)+

2(10

00-2

00)=

4300

mm

Ak

=13

50·8

00=

1080

000

mm

2

Fig

.6.2

Ring

sect

ion

subj

ecte

dto

tors

ion

and

shea

r

The

max

imum

equi

vale

ntsh

eari

nea

chof

the

verti

calm

embe

rsis

(zre

fers

toth

ele

ngth

ofth

eve

rtica

lmem

ber)

:

V* E

d=

VEd

/2+

(TEd

·z)/

2·A

k=

[130

010

3 /2+

(700

106

1350

)/(2

1.08

106 )]

10-3

=10

87kN

Ver

ifica

tion

ofco

mpr

esse

dco

ncre

tew

ithco

t=1

.Itr

esul

ts:

VR

d,m

ax=

tzf cd

sin

cos

=20

013

5010

.50.

707

0.70

7=

1417

kN

>V

* Ed

Page 20: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-11

Tabl

eof

Cont

ent

Det

erm

inat

ion

ofan

gle

:

*o

Ed

cd

2V1

12

1087

000

arcs

inar

csin

25.0

32

ftz

210

.520

013

50he

nce

cot

=2.

14

Rei

nfor

cem

ento

fver

tical

mem

bers

:

(Asw

/s)=

V* E

d/(z

f yd

cot

)=(1

087

103

)/(13

502.

14)=

0.86

5m

m2

/mm

whi

chca

nbe

carr

ied

outw

ith2-

legs

12m

mba

rs,p

itch

200

mm

;pitc

his

inac

cord

ance

with

[9.2

.3(3

)-EC

2].

Rei

nfor

cem

ento

fhor

izon

talm

embe

rs,s

ubje

cted

toto

rsio

non

ly:

(Asw

/s)=

T Ed

/(2A

kf y

dco

t)=

700

106

/(21.

0810

643

52.

14)=

0.34

8m

m2

/mm

whi

chca

nbe

carr

ied

outw

ith8

mm

wid

e,2

legs

stirr

ups,

pitc

h20

0m

m.

Long

itudi

nalr

einf

orce

men

tfor

tors

ion:

Asl

=T E

du k

cot

/(2A

kf y

d)=

700

106

4300

2.14

/(210

8000

043

5)=

6855

mm

2

tobe

dist

ribut

edon

the

sect

ion,

with

parti

cula

ratte

ntio

nto

the

corn

erba

rs.

Long

itudi

nalr

einf

orce

men

tfor

shea

r:

Asl

=V

Edco

t/(

2f y

d)=

1300

000

2.14

/(243

5)=

3198

mm

2

Tobe

plac

edat

the

low

eren

d.

EC2�

wor

ked

exam

ples

6-12

Tabl

eof

Cont

ent

EX

AM

PL

E6.

7Sh

ear�

Tor

sion

inte

ract

ion

diag

ram

s[E

C2

clau

se6.

3]

Fig

.6.3

Rect

angu

lars

ectio

nsu

bjec

ted

tosh

eara

ndto

rsio

n

Exam

ple:

full

rect

angu

lars

ectio

nb

=30

0m

m,h

=50

0m

m,z

=400

mm

(Fig

.6.3

)

Mat

eria

ls:

f ck=

30M

Pa

f cd=

0.85

·(30/

1.5)

=17

.0M

Pa

300.

71

0.61

625

0;

f cd=

10.5

MPa

f yk

=45

0M

Pa;f

yd=

391

MPa

cw=

1

Geo

met

ric

elem

ents

A=

1500

00m

m2

u=

1600

mm

t=A

/u=

94m

m

Ak

=(5

00�

94)

(300

-94)

=83

636

mm

2

Ass

umpt

ion:

=26

.56o

(cot

=2.

0)

Itre

sults

:VR

d,m

ax=

cwb w

zf cd

/(co

t+

tan

)=

10.5

300

400/

(2+0

.5)=

504

kN

and

fort

heta

ken

z=

400

mm

T Rd,

max

=2

10.5

8363

694

0.44

710.

8945

=66

kNm

resi

stan

thol

low

sect

ion

Page 21: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-13

Tabl

eof

Cont

ent

Fig

.6.4

.V-T

inte

ract

ion

diag

ram

forh

ighl

yst

ress

edse

ctio

n

The

diag

ram

issh

own

inFi

g.6.

4.Po

ints

belo

wth

est

raig

htlin

eth

atco

nnec

tsth

ere

sist

ance

valu

eson

the

two

axis

repr

esen

tsaf

ety

situ

atio

ns.F

orin

stan

ce,i

fVEd

=35

0kN

ista

ken,

itre

sults

that

the

max

imum

com

patib

leto

rsio

nm

omen

tis2

0kN

m.

On

the

figur

eot

herd

iagr

ams

inre

latio

nw

ithdi

ffer

ent

valu

esar

esh

own

asdo

tted

lines

.

Seco

ndca

se:l

ight

actio

nef

fect

sSa

me

sect

ion

and

mat

eria

lsas

inth

epr

evio

usca

se.T

hesa

fety

cond

ition

(abs

ence

ofcr

acki

ng)i

sexp

ress

edby

:

T Ed/T

Rd,

c+

VEd

/VR

d,c

1[(

6.31

)-EC

2]

whe

reT R

d,c

isth

eval

ueof

thet

orsio

ncr

acki

ngm

omen

t:

=f ct

d=

f ctk

/c=

2.0/

1.5

=1.

3M

Pa(f

ctkde

duct

edfr

omTa

ble

[3.1

-EC

2]).

Itre

sults

ther

efor

e:

T Rd,

c=

f ctd

t2A

k=

1.3

942

8363

6=

20.4

kNm

VR

d,c

=1/

3Rd

,cl

ckw

Ck

100

fb

d

Inth

isex

pres

sion

,=

0.01

;mor

eove

r,it

resu

lts:

CR

d,c=

0.18

/1.5

=0.

12

200

k1

1.63

500

1/3

1/3

1/3

lck

100

f10

00.

0130

30

EC2�

wor

ked

exam

ples

6-14

Tabl

eof

Cont

ent

Taki

ngd

=45

0m

mit

resu

lts:

VR

d,c=

0,12

1.63

(30)

1/3

300

450

=82

.0kN

The

diag

ram

issh

own

inFi

g.6.

5Th

ese

ctio

n,in

the

rang

eof

actio

nef

fect

sde

fined

byth

ein

tera

ctio

ndi

agra

m,s

houl

dha

vea

min

imal

rein

forc

emen

tin

acco

rdan

cew

ith[9

.2.2

(5)-

EC2]

and

[9.2

.2(6

)-EC

2].N

amel

y,th

em

inim

alqu

antit

yof

stirr

ups

mus

tbe

inac

cord

ance

with

[9.5

N-E

C2]

,whi

chpr

escr

ibes

fors

hear

:

(Asw

/sb w

) min

=(0

.08

f ck)/f

yk=

(0.0

830

)/450

=0.

010

with

snot

larg

erth

an0.

75d

=0,

.75

450

=33

7m

m.

Bec

ause

ofth

eto

rsio

n,st

irrup

sm

ustb

ecl

osed

and

thei

rpitc

hm

ustn

otbe

larg

erth

anu/

8,i.e

.200

mm

.For

inst

ance

,stir

rups

of6

mm

diam

eter

with

180

mm

pitc

hca

nbe

plac

ed.I

tre

sults

:Asw

/s.b

w=

228

/(180

300)

=0.

0010

Fig

.6.5

V-T

inte

ract

ion

diag

ram

forl

ight

lyst

ress

edse

ctio

n

Page 22: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-15

Tabl

eof

Cont

ent

EX

AM

PL

E6.

8.W

allb

eam

[EC

2cl

ause

6.5]

Geo

met

ry:5

400

x30

00m

mbe

am(d

epth

b=

250

mm

),40

0x

250

mm

colu

mns

,col

umns

rein

forc

emen

t620

We

stat

eth

atth

est

rutl

ocat

ion

C 2is

200

cmfr

omth

ebo

ttom

rein

forc

emen

t,so

that

the

inne

rdr

ive

arm

iseq

ualt

oth

eel

astic

solu

tion

inth

eca

seof

aw

allbe

amw

ithra

tio1/

h=2,

that

is0.

67h;

itsu

gges

tsto

use

the

rang

e(0

.60.

7)·l

asva

lues

fort

hele

vera

rm,l

ower

than

the

case

ofa

slend

erbe

amw

ithth

esa

me

span

.

Fig

.6.6

5400

x30

00m

mwa

llbe

am.

Mat

eria

ls:co

ncre

teC2

5/30

f ck=

25M

Pa,s

teel

B450

Cf yk

=45

0M

Pa

2ck

cd0.

85f

0.85

25f

14.1

7N

/mm

1.5

1.5

,

yk2

yd

f45

0f

391.

3N

/mm

1.15

1.15

node

scom

pres

sive

stre

ngth

:

com

pres

sed

node

s ck

21R

d,m

ax1

cd

f1-

2525

0=

kf

=1.

181-

14.1

7=

15N

/mm

0.85

250

node

sten

sione

d�

com

pres

sed

byan

chor

logs

ina

fixed

dire

ctio

n

EC2�

wor

ked

exam

ples

6-16

Tabl

eof

Cont

ent

ck

22R

d,m

ax2

cd

f1-

2525

0=

kf

=1-

14.1

7=

12.7

5N

/mm

0.85

250

node

sten

sione

d�

com

pres

sed

byan

chor

logs

indi

ffere

ntdi

rect

ions

ck

23R

d,m

ax3

cd

f1-

2525

0=

kf

=0.

881-

14.1

7=

11.2

2N

/mm

0.85

250

Act

ions

Dist

ribut

edlo

ad:1

50kN

/mup

pers

urfa

cean

d15

0kN

/mlo

wer

surf

ace

Col

umns

reac

tion

R=

(150

+15

0)5.

40/2

=81

0kN

Eva

luat

ionof

stress

esin

latti

ceba

rs

Equi

libriu

mno

de1

1ql

C40

5kN

2

Equi

libriu

mno

de3

3R

C96

6kN

sen

(whe

re20

00ar

ctg

56.9

813

00)

kN52

6co

sC

T3

1

Equi

libriu

mno

de2

C2

=C

3cos

=T 1

=52

6kN

Equi

libriu

mno

de4

kN40

52lq

T 2

Tens

ionro

ds

The

tens

ion

rod

T 1re

quire

sast

eela

rea

notl

ower

than

:

2s1

5260

00A

1344

mm

391.

,3w

eus

e6

18=

1524

mm

2 ,

the

rein

forc

emen

toft

helo

wer

tens

ion

rod

are

loca

ted

atth

ehe

ight

of0,

12h

=36

0m

m

The

tens

ion

rod

T 2re

quire

sast

eela

rea

notl

ower

than

:

2s1

4050

00A

1035

mm

391.

3W

eus

e4

20=

1257

mm

2

Page 23: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-17

Tabl

eof

Cont

ent

Nod

esve

rifica

tion

Nod

e3

The

node

geom

etry

isun

ambi

guou

slyde

fined

byth

eco

lum

nw

idth

,th

ew

allde

pth

(250

mm

),th

ehe

ight

ofth

esid

eon

whi

chth

elo

wer

bars

are

dist

ribut

edan

dby

the

stru

tC3

fall

(Fig

.6.7

)

Fig

.6.7

Nod

e3,

left

supp

ort.

The

node

3is

aco

mpr

esse

d-st

ress

edno

deby

asin

gle

dire

ctio

nre

info

rcem

enta

ncho

r,th

enit

ism

anda

tory

tove

rify

that

the

max

imal

conc

rete

com

pres

sion

isno

thig

hert

han

the

valu

e:

22R

d,m

ax12

.75

N/m

m

2c1

2Rd,

max

8100

008.

1N

/mm

400

250

Rem

ark

asth

eve

rifica

tion

ofth

eco

lum

nco

ntac

tpr

essur

eis

satis

fied

even

with

out

taki

ngin

toac

coun

tth

elon

gitud

inal

reinf

orcem

ent(

620

)pres

ent

inth

ecolu

mn.

2c2

2Rd,

max

9660

007.

27N

/mm

531.

625

0

EC2�

wor

ked

exam

ples

6-18

Tabl

eof

Cont

ent

EX

AM

PL

E6.

9.T

hick

shor

tcor

bel,

a c<

h c/2

[EC

2cl

ause

6.5]

Geo

met

ry:2

50x

400

mm

cant

ileve

r(w

idth

b=

400

mm

),15

0x

300

load

plat

e,be

amb

xh

=40

0x

400

mm

Fig

.6.8

250

x40

0m

mth

ick

cant

ileve

rbea

m.

Fig

.6.9

Can

tilev

erbe

amS&

Tm

odel

.

Mat

eria

ls:co

ncre

teC3

5/45

f ck=

35M

Pa,s

teel

B450

Cf yk

=45

0M

Pa

2ck

cd0.

85f

0.85

35f

==

=19

.83

N/m

m1.

51.

5,

yk2

yd

f45

0f

391.

3N

/mm

1.15

1.15

node

scom

pres

sive

stre

ngth

:

com

pres

sed

node

s ck

21R

d,m

ax1

cd

f1-

3525

0=

kf

=1.

181-

19.8

3=

20.1

2N

/mm

0.85

250

Page 24: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-19

Tabl

eof

Cont

ent

node

sten

sione

d�

com

pres

sed

byan

chor

logs

ina

fixed

dire

ctio

n

ck

22R

d,m

ax2

cd

f1-

3525

0=

kf

=1-

19.8

3=

17.0

5N

/mm

0.85

250

node

sten

sione

d�

com

pres

sed

byan

chor

logs

indi

ffere

ntdi

rect

ions

ck

23R

d,m

ax3

cd

f1-

3525

0=

kf

=0.

881-

19.8

3=

15N

/mm

0.85

250

Act

ions

F Ed

=70

0kN

Load

ecce

ntric

ityw

ithre

spec

tto

the

colu

mn

side:

e=

125

mm

(Fig

.6.8

)

The

beam

verti

cals

trutw

idth

isev

alua

ted

byse

tting

the

com

pres

sive

stre

sseq

ualt

o1R

d,m

ax:

Ed1

1Rd,

max

F70

0000

xm

mb

20.1

240

087

the

node

1is

loca

ted

x 1/2

44m

mfr

omth

eou

terc

olum

nsid

e(F

ig.6

.9)

We

stat

eth

atth

eup

per

rein

forc

emen

tis

loca

ted

40m

mfr

omth

eup

per

cant

ileve

rsid

e;th

edi

stan

cey 1

ofth

eno

de1

from

the

low

erbo

rder

isev

aluat

edse

tting

the

inte

rnal

driv

ear

mz

equa

lto

0.8

d(z

=0,

836

0=

288

mm

):

y 1=

0.2d

=0.

2·36

0=

72m

m

rota

tiona

lequ

ilibr

ium

:Ed

cF

aF

zc

7000

00(1

2544

)F

288

ct

7000

00(1

2544

)F

F41

0763

N41

1kN

288

node

1veri

ficat

ion:

22

c1R

d,m

ax1

F41

1000

7N

/mm

N/m

mb

2y

400

27

.14

20.1

22

Mai

nup

perr

einfor

cemen

tdesi

gn:

2t

sydF

4110

00A

1050

mm

f39

1.3

we

use

814

(As=

1232

mm

2 )

Seco

ndar

yupp

errei

nfor

cemen

tdesi

gn:

The

beam

prop

osed

inE

C2is

inde

term

inat

e,th

enit

isno

tpos

sible

toev

aluat

eth

est

ress

esfo

rea

chsin

gle

bar

byeq

uilib

rium

equa

tions

only

,but

we

need

tokn

owth

est

iffne

ssof

the

two

elem

enta

rybe

ams

show

nin

Fig.

6.10

inor

der

tom

ake

the

parti

tion

ofth

edi

agon

alst

ress

senF

cosF

FEd

cdi

agbe

twee

nth

em;

EC2�

wor

ked

exam

ples

6-20

Tabl

eof

Cont

ent

Fig

.6.1

0S&

Tm

odel

reso

lutio

nin

two

elem

enta

rybe

amsa

ndpa

rtiti

onof

the

diag

onal

stres

sFdi

ag.

base

don

the

trend

ofm

ainco

mpr

essiv

est

ress

esre

sulti

ngfr

omlin

eare

lastic

analy

sisat

finite

elem

ents

,som

ere

sear

cher

ofSt

uttg

arth

ave

dete

rmin

edth

etw

ora

tesi

nw

hich

F diag

isdi

vide

d,an

dth

eyha

vepr

ovid

edth

efo

llow

ing

expr

essio

nof

stre

ssin

the

seco

ndar

yre

info

rcem

ent

(MC9

0pa

r.6.

8.2.

2.1)

:

wd

cEd

c

z28

82

12

1a

125

44F

F41

121

1kN

3F

/F3

700

/411

22

wd

sw1

sydF

2110

00A

539

mm

kA

0.25

1232

308

mm

f39

1.3

we

use

5st

irrup

s10

,dou

ble

arm

ed(A

sw=

785

mm

2 )

node

2ve

rifica

tion,

below

thel

oad

plat

e:

The

node

2is

atie

d-co

mpr

esse

dno

de,

whe

reth

em

ainre

info

rcem

ent

isan

chor

ed;

the

com

pres

sive

stre

ssbe

low

the

load

plat

eis: 2

2Ed

2Rd,

max

F70

0000

15.5

6N

/mm

17.0

5N

/mm

150

300

4500

0

Page 25: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-21

Tabl

eof

Cont

ent

EX

AM

PL

E6.

10T

hick

cant

ileve

rbea

m,a

c>

h c/2

[EC

2cl

ause

6.5]

Geo

met

ry:3

25x

300

mm

cant

ileve

rbea

m(w

idth

b=

400

mm

),15

0x

220

mm

load

plat

e,40

0x

400

mm

colu

mn

Fig

.6.1

132

5x

300

mm

cant

ileve

r.F

ig.6

.12

Can

tilev

erS&

Tm

odel

.Th

em

odel

prop

osed

inE

C2(F

ig.6

.12)

isin

dete

rmin

ate,

then

asin

the

prev

ious

exam

ple

one

mor

ebo

unda

ryco

nditi

onis

need

edto

evalu

ate

the

stre

sses

valu

esin

the

rods

;Th

est

ress

F wd

inth

eve

rtica

lten

sion

rod

isev

alua

ted

assu

min

ga

linea

rre

latio

nbe

twee

nF w

d

and

the

ava

lue,

inth

era

nge

F wd

=0

whe

na

=z/

2an

dF w

d=

F Ed

whe

na

=2

z.Th

isas

sum

ptio

nco

rres

pond

sto

the

stat

emen

tth

atw

hen

az/

2(a

very

thick

cant

ileve

r),th

ere

sista

ntbe

amis

the

beam

1on

ly(F

ig.6

.13a

)and

whe

na

2z

the

beam

2on

ly(F

ig.6

.13b

).

a)b)

Fig

.6.1

3.El

emen

tary

beam

soft

heS&

Tm

odel

.

EC2�

wor

ked

exam

ples

6-22

Tabl

eof

Cont

ent

Ass

umed

this

stat

emen

t,th

eex

pres

sion

forF

wd

is:

F wd=

F w1

a+

F w2

whe

nth

etw

oco

nditi

ons

wd

zF

(a)

02

and

F wd

(a=

2z)

=F E

dar

eim

pose

d,so

me

trivi

al

algeb

rale

adst

o:

Edw

1F

2F

3z

and

Edw

2F

F3

;

inco

nclu

sion,

the

expr

essio

nfo

rFw

das

afu

nctio

nof

ais

the

follo

win

g:

EdEd

wd

EdF

F2

2a/z

1F

aF

3z

33

.

Mat

eria

ls:co

ncre

teC3

5/45

f ck=

35M

Pa,s

teel

B450

Cf yk

=45

0M

Pa

2ck

cd0.

85f

0,85

35f

19.8

3N

/mm

1.5

1.5

,

yk2

yd

f45

0f

391.

3N

/mm

1.15

1.15

Nod

esco

mpr

essio

nre

sista

nce

(sam

eva

lues

ofth

epr

evio

usex

ampl

e):

Com

pres

sed

node

s2

1Rd,

max

2N

/mm

0.12

tied-

com

pres

sed

node

swith

tens

ion

rods

inon

edi

rect

ion

22R

d,m

axN

/mm

17.0

5

tied-

com

pres

sed

node

swith

tens

ion

rods

indi

ffere

ntdi

rect

ions

23R

d,m

ax1

N/m

m5

Act

ions

:

F Ed

=50

0kN

Load

ecce

ntric

ityw

ithre

spec

tto

the

colu

mn

oute

rsid

e:e

=20

0m

m

The

colu

mn

verti

cals

trutw

idth

isev

aluat

edse

tting

the

com

pres

sive

stre

sseq

ualt

o1R

d,m

ax:

Ed1

1Rd,

max

F50

0000

x62

mm

b20

.12

400

node

1is

loca

ted

x 1/2

=31

mm

from

the

oute

rsid

eof

the

colu

mn;

the

uppe

rre

info

rcem

enti

sst

ated

tobe

40m

mfr

omth

eca

ntile

ver

oute

rsid

e;th

edi

stan

cey 1

ofth

eno

de1

from

the

low

erbo

rder

isca

lcul

ated

setti

ngth

ein

tern

aldr

ive

arm

zto

be0,

8d

(z=

0,8

260

=20

8m

m):

y 1=

0.2d

=0.

2·26

0=

52m

m

Page 26: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-23

Tabl

eof

Cont

ent

rota

tiona

lequ

ilibr

ium

:

1Ed

cx

Fa

Fz

5000

00(2

00+

31)=

F c. 20

8

ct

5000

00(2

0031

)F

F55

5288

N55

6kN

208

node

1ve

rifica

tion

22

c1R

d,m

ax1

F55

6000

==

=13

.37

N/m

m=

20.1

2N

/mm

b2

y40

02

52

Mai

nup

perr

einfor

cemen

tdesi

gn:

2t

sydF

5560

00A

1421

mm

f39

1.3

we

use

816

(As=

1608

mm

2 )

Seco

ndar

yrei

nfor

cemen

tdesi

gn:

(the

expr

essio

nde

duce

dat

the

begi

nnin

gof

this

exam

ple

isus

ed)

wEd

a2

1z

FF

204

kN3

2w

wydF

2040

00A

521

mm

f39

1.3

EC2

sugg

ests

am

inim

umse

cond

ary

rein

forc

emen

tof:

2Ed

w2

ydF50

0000

Ak

0.5

639

mm

f39

1.3

we

use

3st

irrup

s12

(As=

678

mm

2 )

node

2ve

rifica

tion,

below

thel

oad

plat

e:

The

node

2is

aco

mpr

esse

d-st

ress

edno

de,i

nw

hich

the

main

rein

forc

emen

tis

anch

ored

;the

com

pres

sive

stre

ssbe

low

the

load

plat

eis: 2

2Ed

2Rd,

max

F50

0000

15.1

5N

/mm

17.0

5N

/mm

150

220

3300

0

EC2�

wor

ked

exam

ples

6-24

Tabl

eof

Cont

ent

EX

AM

PL

E6.

11G

erbe

rbea

m[E

C2

clau

se6.

5]

Two

diffe

rent

stru

t-tie

truss

esca

nbe

cons

ider

edfo

rthe

desig

nof

aG

erbe

rbea

m,e

vent

ually

ina

com

bine

dco

nfig

urat

ion

[EC2

(10.

9.4.

6)],

(Fig

.6.

14).

Even

ifth

eE

C2all

ows

the

poss

ibili

tyto

use

only

one

stru

tand

then

only

one

rein

forc

emen

tarr

ange

men

t,w

ere

mar

kas

the

sche

me

b)re

sults

tobe

poor

unde

rlo

ad,b

ecau

seof

the

com

plet

elac

kof

rein

forc

emen

tfo

rth

ebo

ttom

bord

erof

the

beam

.It

seem

sto

beop

portu

neto

com

bine

the

type

b)re

info

rcem

entw

ithth

ety

pea)

one,

and

the

latte

rwill

carr

yat

least

half

ofth

ebe

amre

actio

n.

On

the

othe

rhan

d,if

only

the

sche

me

a)is

used

,iti

snec

essa

ryto

cons

ider

alo

ngitu

dina

ltop

rein

forc

emen

tto

anch

orbo

thth

eve

rtica

lstir

rups

and

the

conf

inin

gre

info

rcem

ent

ofth

etil

ted

stru

tC1.

a)b)

Fig

.6.1

4Po

ssib

lestr

utan

dtie

mod

elsf

ora

Ger

berb

eam

.

Her

eafte

rwe

repo

rtth

epa

rtitio

nof

the

supp

ortr

eact

ion

betw

een

the

two

truss

es.

Mat

erial

s:

conc

rete

C25/

30f ck

=25

MPa

,

stee

lB4

50C

f yk=

450

MPa

Es=

2000

00M

Pa[(3

.2.7

(4)-E

C2]

2ck

cd0.

85f

0.85

25f

14.1

7N

/mm

1.5

1.5

,

yk2

yd

f45

0f

391.

3N

/mm

1.15

1.15

Act

ions

:

Dist

ribut

edlo

ad:2

50kN

/m

Beam

spam

:800

0m

m

R Sdu

=10

00kN

Bend

ing

mom

enti

nth

ebe

amm

id-s

pam

:MSd

u=

2000

kNm

Beam

sect

ion:

bx

h=

800

x14

00m

m

Botto

mlo

ngitu

dina

lrein

forc

emen

t(A

s):10

24=

4524

mm

2

Page 27: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-25

Tabl

eof

Cont

ent

Top

long

itudi

nalr

einfo

rcem

ent

(As�)

:820

=25

13m

m2

Trus

sa)R

=R S

du/2

=50

0kN

Defi

nitio

nof

thet

russ

rods

posit

ionTh

eco

mpr

esse

dlo

ngitu

dina

lbar

has

aw

idth

equa

lto

the

dept

hx

ofth

ese

ctio

nne

utra

laxi

san

dth

enit

isx/

2fr

omth

eto

pbo

rder

;the

dept

hof

the

neut

rala

xis

isev

aluat

edfr

omth

ese

ctio

ntra

nslat

ion

equi

libriu

m:

0.8

bx

f cd+

E s� s

A� s

=f y

dA

s

Fig

.6.1

5Tr

ussa

.

'dx

x0,

0035

' sw

here

d�=

50m

mis

the

dist

ance

ofth

eup

pers

urfa

cere

info

rcem

ent

cds

syd

sx

500.

8bxf

E0.

0035

A'

fA

xan

dth

en:

x=

99m

m

yd' s

s

f0.

0035

391.

399

500.

0017

30.

0019

699

E20

0000

then

the

com

pres

sed

stee

lstra

inre

sults

low

erth

anth

estr

ainin

the

elas

ticlim

it,as

stat

edin

the

calcu

latio

n;

the

com

pres

sive

stre

ssin

the

conc

rete

is

C=

0.8

bx

f cd=

0.8·

800·

99·1

4.17

(app

lied

at0.

4x

40m

mfr

omth

eup

pers

urfa

ce)

whi

leth

eto

pre

info

rcem

ents

tress

is:

C�=

E s� s

A� s

=20

0000

·0.0

0173

·251

3

EC2�

wor

ked

exam

ples

6-26

Tabl

eof

Cont

ent

(app

lied

at50

mm

from

the

uppe

rsur

face

)

the

com

pres

sion

net

forc

e(C

+C�

)re

sults

tobe

appl

iedat

45m

mfr

omth

ebe

amup

per

surfa

ce,t

hen

the

horiz

onta

lstru

thas

the

axis

at67

5�

50-4

5=

580

mm

from

the

tens

ion

rod

T2.

Cal

cula

tion

ofth

etru

ssro

dsstr

esses

Nod

e1

equi

libriu

m:

53,7

742

558

0ar

ctg

1R

C62

0kN

sin

kN36

6co

sC

T1

2

Nod

e2

equi

libriu

m:

580

arct

g38

,66

725

23

2T

cos4

5C

cos

C

23

Csi

nC

sin4

5

22

TC

260

kNsi

nco

s

32

sin

CC

230

kNsi

n45

Nod

e3

equi

libriu

m:

T 1=

C1

sin

+C

2si

n=

663

kNTe

nsion

rods

desig

n

the

tens

ion

rod

T 1ne

edsa

stee

lare

ano

tlow

erth

an:

2s1

6630

00A

1694

mm

391.

3

we

use

5st

irrup

s16

doub

lear

m(A

sl=

2000

mm

2 )

the

tens

ion

rod

T 2ne

edsa

stee

lare

ano

tlow

erth

an:

2s1

3660

00A

935

mm

391.

3

we

use

516

(Asl

=10

00m

m2 ).

Trus

sb)R

=R S

du/2

=50

0kN

Fig

.6.1

6C

alcu

latio

nsc

hem

efo

rthe

trus

sbba

rsstr

esse

s.C

alcu

latio

nof

thet

russ

rods

stress

es

Page 28: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-27

Tabl

eof

Cont

ent

node

1eq

uilib

rium

C�1

=50

0kN

node

2eq

uilib

rium

C� 2

=C� 1

=50

0kN

kN70

7C

'2

T'1

1

node

3eq

uilib

rium

C� 3

=T�

1=

707

kN

T�2

=(T� 1

+C� 3

)·cos

45°

=10

00kN

Tens

ionro

ds

fort

ensio

nro

dT�

2it

isne

cess

ary

toad

opta

stee

lare

ano

tlow

erth

an:

2s1

1000

000

A25

56m

m39

1.3

624

=27

12m

m2

are

adop

ted,

alo

wer

rein

forc

emen

tar

eaw

ould

besu

fficie

ntfo

rte

nsio

nro

dT�

1bu

tfo

rqu

estio

nof

bar

anch

orin

gth

esa

me

rein

forc

emen

tasi

nT�

2is

adop

ted.

EC2�

wor

ked

exam

ples

6-28

Tabl

eof

Cont

ent

EX

AM

PL

E6.

12Pi

leca

p[E

C2

clau

se6.

5]

Geo

met

ry:

4500

x45

00m

mpl

inth

(thick

ness

b=15

00m

m),

2000

x70

0m

mco

lum

ns,

diam

eter

800

mm

piles

Fig

.6.1

7Lo

gpl

inth

onpi

lings

.

Mat

eria

ls:co

ncre

teC2

5/30

f ck=

25M

Pa,s

teel

B450

Cf yk

=45

0M

Pa2

ckcd

0.85

f0.

8525

f14

.17

N/m

m1.

51.

5,

yk2

yd

f45

0f

391.

3N

/mm

1.15

1.15

Nod

esco

mpr

essio

nre

sista

nce

(sam

eva

lues

asin

the

exam

ple

6.8)

Com

pres

sed

node

s1R

d,m

ax=

15N

/mm

2

tied-

com

pres

sed

node

swith

tens

ion

rods

inon

edi

rect

ion

2Rd,

max

=12

.75

N/m

m2

tied-

com

pres

sed

node

swith

tens

ion

rods

indi

ffere

ntdi

rect

ions

3Rd,

max

=11

.22

N/m

m2

Pede

stal

pile

NSd

=20

00kN

MSd

=40

00kN

m

Page 29: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-29

Tabl

eof

Cont

ent

Tied

rein

forc

emen

tin

the

pile:

826

(As=

4248

mm

2 )

The

com

pres

sive

stre

ssF c

inth

eco

ncre

tean

dth

est

eelt

ensio

nF s

onth

epe

dest

alpi

lear

eev

aluat

edfr

omth

eU

LSve

rific

atio

nfo

rnor

mal

stre

sses

ofth

ese

ctio

nits

elf:

F s=

f ydA

s=

391.

3·42

48=

1662

242

N=

1662

kN

NSd

=0.

8b

xf cd�

F s·

·x·

x=

462

mm

The

com

pres

sive

stre

ssin

the

conc

rete

is:

C=

0.8

bx

f cd=

0.8·

700·

462·

14.1

7=

3666

062

N=

3666

kN

(app

lied

at0,

4x

185

mm

from

the

uppe

rsur

face

)

piles

stre

ss

pile

stre

sses

are

evalu

ated

cons

ider

ing

the

colu

mn

actio

nstra

nsfe

rin

two

step

s:

inth

efir

stst

ep,

the

trans

fero

fthe

forc

esF c

eF s

happ

ensi

nth

epl

ane

1(F

ig.6

.17)

tillt

oth

eor

thog

onal

plan

es2

and

3,th

enin

the

seco

ndst

epth

etra

nsfe

ris

insid

eth

epl

anes

2an

d3

tillt

oth

epi

les;

the

truss

-tie

beam

inFi

g.6.

18is

relat

ive

toth

etra

nsfe

rin

the

plan

e1:

com

pres

sion:

A�=

(MSd

/3.0

0+

NSd

/2)=

(400

0/3.

00+

2000

/2)=

2333

kN

tens

ion:

B�=

(MSd

/3.0

0-N

Sd/2

)=(4

000/

3.00

-200

0/2)

=33

3kN

fore

ach

com

pres

sed

pile

:A

=A�/

2=

1167

kN

fore

ach

tied

pile:

B=B�

/2=

167

kN

Inth

eev

aluat

ion

ofst

ress

eson

pile

s,th

epl

inth

own

weig

htis

cons

ider

edne

glig

ible

.

Fig

.6.1

8.S&

Tm

odel

inth

epl

ane

1.

EC2�

wor

ked

exam

ples

6-30

Tabl

eof

Cont

ent

11=

arct

g(1

300

/86

0)=

56.5

°12

=ar

ctg

(130

0/

600)

=65

.2°

T 10

=F s

=16

62kN

T 11

=A�c

ot11

=23

33co

t26.

5°=

1544

kNT 1

2=

B�co

t12

=33

3co

t65.

2°=

154

kN

Fig

.6.1

9Tr

usse

sin

plan

2an

din

plan

3.

13=

arct

g(1

300

/13

25)=

44.5

°T 1

3=

A=

1167

kNT 1

4=

Aco

t13

=11

67co

t44.

5°=

1188

kNT 1

5=

Bco

t13

=16

7co

t44.

5°=

170

kNT 1

6=

B=

167

kN

desig

nof

tens

ion

rods

Tabl

e6.

3

Tens

ion

rod

Forc

e(k

N)

Requ

ired

rein

forc

emen

t(m

m2 )

Bars

10(p

linth

tied

rein

forc

emen

t)16

6242

488

2611

1544

3946

924

1215

439

41

12/2

0(6

12)

1311

6729

82st

irrup

s10

2014

1188

3036

724

1517

043

41

12/2

0(5

12)

1616

742

7Pi

lere

info

rcem

ent

Page 30: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-31

Tabl

eof

Cont

ent

Fig

.6.2

0.Sc

hem

atic

plac

emen

tofr

einf

orce

men

ts.

Nod

esve

rific

atio

nCo

ncen

trate

dno

des

are

only

pres

enta

tthe

pede

stal

pile

and

onth

epi

les

top.

Inth

ese

latte

r,th

eco

mpr

essiv

est

ress

esar

eve

rysm

allas

aco

nseq

uenc

eof

the

pile

ssec

tion

large

area

.:

2c

22

A23

3300

04.

64N

mm

r40

0

EC2�

wor

ked

exam

ples

6-32

Tabl

eof

Cont

ent

EX

AM

PL

E6.

13V

aria

ble

heig

htbe

am[E

C2

clau

se6.

5]

Geo

met

ry:l

engt

h22

500

mm

,rec

tang

ular

sect

ion

300

x35

00m

man

d30

0x

2000

mm

Fig

.6.2

1Va

riab

lehe

ight

beam

Mat

eria

ls:co

ncre

teC3

0/37

f ck=

30M

Pa,s

teel

B450

Cf yk

=45

0M

Pa

2ck

cd0.

85f

0.85

3f

17N

/mm

1.5

1,5

0,

yk2

yd

f45

0f

391.

3N

/mm

1.15

1.15

Nod

esco

mpr

essiv

ere

sista

nce:

com

pres

sed

node

s(E

C2

eq.6

.60)

ck

21R

d,m

ax1

cd

f1-

3025

0=

kf

=1.

181-

17=

17.6

5N

/mm

0.85

250

tied-

com

pres

sed

node

swith

tens

ion

rods

inon

edi

rect

ion

ck

22R

d,m

ax2

cd

f1-

3025

0=

kf

=1-

17=

14.9

6N

/mm

0.85

250

tied-

com

pres

sed

node

swith

tens

ion

rods

indi

ffere

ntdi

rect

ions

ck

23R

d,m

ax3

cd

f1-

3025

0=

kf

=0.

881-

17=

13.1

6N

/mm

0.85

250

load

s

F=

1200

kN

(the

own

wei

ghto

fthe

beam

isne

glig

ible)

Page 31: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-33

Tabl

eof

Cont

ent

stru

t&tie

mod

elid

entif

icat

ion

Beam

parti

tioni

ngin

two

regi

onsB

and

D

The

regi

onst

andi

ngon

the

mid

dle

sect

ion

isa

cont

inui

tyre

gion

(B),

whi

leth

ere

main

ing

part

ofth

ebe

amis

com

pose

dof

Dty

pere

gion

s.

The

boun

dary

cond

ition

sfor

the

stre

ssin

the

regi

onB.

Fig

.6.2

2Id

entif

icat

ion

ofB

and

Dre

gion

s.

Stre

sses

eval

uatio

nfo

rthe

bars

ofth

eS&

Tm

odel

T max

=12

00kN

Mm

ax=

1200

3.00

=36

00kN

m=

3.6

109

Nm

m

Fig

.6.2

3Sh

eara

ndbe

ndin

gm

omen

tdia

gram

s.

Calcu

latio

nof

stre

sses

inth

ere

gion

B

The

stre

ss-b

lock

diag

ram

isus

edfo

rthe

conc

rete

com

pres

sive

stre

sses

dist

ribut

ion;

rota

tiona

lequ

ilibr

ium

:

f cd0.

8·x·

b·(d�

0.4

x)=

3.6·

109

17·0

.8·x

·300

·(190

0�

0.4

x)=

3.6·

109

7752

000·

x�

1632

·x2

=3.

610

9x

=52

2m

m

C=

f cd0.

8·x·

b=

17·0

.8·5

22·3

00=

2129

760

N=

2130

kN

EC2�

wor

ked

exam

ples

6-34

Tabl

eof

Cont

ent

Iden

tifica

tion

ofbo

unda

ryst

ress

esin

the

regi

onD

Fig

.6.2

4Re

actio

nsan

dbo

unda

ryst

ress

esin

the

regi

onD

.

stru

t&tie

mod

el

Fig.

6.25

show

sth

elo

adpa

ths

char

acte

rized

bySc

hlaic

hin

the

stru

t&tie

mod

elid

entif

icat

ion,

show

nin

Fig.

6.26

.

Fig

.6.2

5Lo

adpa

ths.

Fig

.6.2

6.St

ruta

ndtie

mod

el.

The

stru

tC2

tiltin

gis

3190

arct

g46

.76

3000

whi

leth

est

rutC

4til

ting

is

116

90ar

ctg

48.4

115

00.

Page 32: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-35

Tabl

eof

Cont

ent

The

follo

win

gta

ble

repo

rtsth

eva

lue

fort

hest

ress

esin

the

diffe

rent

beam

elem

ents

.Ta

ble

6.4

C 1Se

est

ress

esev

aluat

ion

inth

ere

gion

B21

30kN

T 1T 1

=C

121

30kN

C 2C

2=

F/si

n(N

ode

Ave

rtica

lequ

ilibr

ium

)16

47kN

T 3T 3

=C

2co

s(N

ode

Aho

rizon

tale

quili

briu

m.)

1128

kNT 2

T 2=

T 3,b

ecau

seC 5

is45

°til

ted

(nod

eC

equi

l.)11

28kN

C 3C

3=

C2

cos

=T 3

(Nod

eB

horiz

onta

lequ

il.)

1128

kNF l

oop

F loo

p=

C 1�

C3

1002

kNC 4

C4

=F l

oop/c

os15

09kN

C 52

TC

25

(Nod

eC

verti

cale

quil.

)15

95kN

Stee

lten

sion

rods

desig

n

EC2

poin

t9.7

sugg

ests

that

the

min

imum

rein

forc

emen

tfor

the

wall

beam

sis

the

0,10

%of

the

conc

rete

area

,and

notl

ess

than

150

mm

2 /m,a

ndit

has

tobe

disp

osed

onbo

thsid

esof

the

struc

tura

lmem

bera

ndin

both

dire

ctio

ns.B

ars

12/

20�

(=56

5m

m2 /m

>0,

10%

300

1000

=30

0m

m2 /m

edi

150

mm

2 /m)a

reus

ed.

The

follo

win

gta

ble

repo

rtsth

eev

aluat

ion

for

the

rein

forc

emen

tar

eare

quire

dfo

rth

eth

ree

tens

ion

bars

T 1,T

2an

dT 3

.Ta

ble

6.5

T 1A

s=

2.13

·106 /3

91.3

=54

43m

m2

1820

=56

55m

m2

T 2A

s=

1.12

8·10

6 /391

.3=

2883

mm

2

on1,

50m

leng

thst

irrup

s12

/10�

2le

gs=

2260

mm

2 /m(2

260

1,50

=33

90m

m2 )

T 3A

s=

1.12

8·10

6 /391

.3=

2883

mm

2

ontw

olay

ers

1020

=31

42m

m2

Ver

ifica

tion

ofno

des

Nod

eA(le

ftsu

ppor

t)

Fig

.6.2

7N

ode

A.

tied-

com

pres

sed

node

swith

tens

ion

rods

inon

edi

rect

ion

[(6.6

1)-E

C2]

2Rd,

max

=14

.96

N/m

m2

EC2�

wor

ked

exam

ples

6-36

Tabl

eof

Cont

ent

Load

ing

plat

ear

ea:

62

c1

2Rd,

max

F1.

210

A80

214

mm

14.9

6

a30

0x

300

mm

plat

e(A

=90

000

mm

2 )isu

sed

the

rein

forc

emen

tfor

the

tens

ion

rod

T 3is

load

edon

two

layer

s(Fi

g.6.

27):

u=

150

mm

a 1=

300

mm

a 2=

300

sin46

.76°

+15

0co

s46.

76°=

219

+10

3=

322

mm

62

2c2

1.64

710

17.0

5N

/mm

14.9

6N

/mm

300

322

uha

sto

behi

gher

(itis

man

dato

rya

rein

forc

emen

ton

mor

eth

antw

olay

ers,

oran

incr

ease

ofth

epl

ate

leng

th);

this

last

choi

ceis

adop

ted,

and

the

leng

this

incr

ease

dfr

om30

0to

400

mm

:

a 2=

400

sin46

.76°

+15

0co

s46.

76°=

291

+10

3=

394

mm

62

2c2

1.64

710

13.9

3N

/mm

14.9

6N

/mm

300

394

Nod

eB

Com

pres

sed

node

s

1Rd,

max

=17

.65

N/m

m2

Fig

.6.2

8N

ode

B.

a 3=

522

mm

(coi

ncid

entw

ithth

ede

pth

ofth

ene

utra

laxi

sin

the

regi

onB)

3

62

23

cC

1.12

810

7.2

N/m

m17

.65

N/m

m30

052

230

052

2lo

adpl

ate

dim

ensio

ns:

61.

210

a*22

7m

m30

017

.65

a30

0x

300

mm

plat

eis

used

Stru

tver

ifica

tion

Page 33: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-37

Tabl

eof

Cont

ent

The

com

pres

sive

rang

efo

rea

chst

rut

(onl

yex

cept

ion,

the

stru

tC 1

,w

hich

stre

ssha

sbe

enve

rifie

dbe

fore

inth

efo

rces

evalu

atio

nfo

rthe

regi

onB)

can

spre

adbe

twee

nth

etw

oen

ds,i

nth

isw

ayth

em

axim

alst

ress

esar

ein

the

node

s.

The

trans

vers

alst

ress

fort

hesp

litof

the

mos

tstre

ssed

stru

t(C 2

)is:

T s0.

25·C

2=

0.25

1647

=41

2kN

;

and

then

,for

the

rein

forc

emen

treq

uire

dto

carr

yth

isst

ress

:

2s

4120

00A

1053

mm

391.

3,

then

the

min

imum

rein

forc

emen

t(1

12/

20�

onbo

thsid

esan

din

both

dire

ctio

ns,t

hati

sa s

=11

30m

m2 /m

)ise

noug

hto

carr

yth

etra

nsve

rsal

stre

sses

.

EC2�

wor

ked

exam

ples

6-38

Tabl

eof

Cont

ent

EX

AM

PL

E6.

14.

3500

kNco

ncen

trat

edlo

ad[E

C2

clau

se6.

5]

3500

kNlo

adon

a80

0x50

0re

ctan

gula

rcol

umn

bya

300x

250

mm

cush

ion

Mat

eria

ls: conc

rete

C30

/37

f ck=

30M

Pa,

stee

lB4

50C

f yk=

450

MPa

Es=

2000

00M

Pa

2ck

cd0.

85f

0.85

30f

17N

/mm

1.5

1.5

,

yk2

yd

f45

0f

391.

3N

/mm

1.15

1.15

,

load

ing

area

Ac0

=30

0·25

0=

7500

0m

m2

dim

ensio

nsof

the

load

dist

ribut

ion

area

d 23

d 1=

3·30

0=

900

mm

b 23

b 1=

3·25

0=

750

mm

max

imal

load

dist

ribut

ion

area

Ac1

=90

0·75

0=

6750

00m

m2

load

dist

ribut

ion

heig

ht

mm

500

250

750

bb

h1

2

mm

600

300

900

dd

h1

2

h=

600

mm

Ulti

mat

eco

mpr

essiv

est

ress

Rdu

c0cd

c1c0

6cd

c0

FA

fA

/A75

000

1767

5000

/750

0038

25kN

3.0

fA

3.0

1775

000

3.82

510

N

Itis

wor

thto

obse

rve

that

the

F Rdu

uppe

rlim

itco

rres

pond

sto

the

the

max

imal

valu

eA

c1=

3A

c0fo

rthe

load

dist

ribut

ion

area

,jus

tasi

nth

isex

ampl

e;th

e35

00kN

load

resu

ltsto

belo

wer

than

F Rdu

.

Rein

forc

emen

tdes

ign

Poin

t[6

.7(4

)-EC

2]re

com

men

dsth

eus

eof

asu

itabl

ere

info

rcem

ent

capa

ble

tosu

stai

nth

etra

nsve

rsal

shrin

kage

stre

sses

and

poin

t[6

.7(1

)P-E

C2]

send

sth

ere

ader

topa

ragr

aph

[(6.5

)-E

C2]t

oan

alyse

this

topi

c.

Inth

isca

seth

ere

isa

parti

aldi

scon

tinui

ty,b

ecau

seth

est

rutw

idth

(500

mm

)is

low

erth

anth

edi

strib

utio

nhe

ight

(600

mm

),th

en:

a=

250

mm

Page 34: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-39

Tabl

eof

Cont

ent

b=

500

mm

Fb

a35

0050

025

0T

437.

5kN

4b

450

0th

est

eela

rea

requ

ired

toca

rry

Tis:

2s

ydT43

7500

A11

18m

mf

391.

3

usin

g10

mm

diam

eter

bars

,15

bars

are

requ

ired

fora

tota

lare

aof:

As=

1578

.5=

1178

mm

2 .

EC2�

wor

ked

exam

ples

6-40

Tabl

eof

Cont

ent

EX

AM

PL

E6.

15Sl

abs1,

2[E

C2

clau

se5.

10�

6.1�

6.2�

7.2�

7.3�

7.4]

As

two

dim

ensi

onal

mem

bera

pres

tress

edco

ncre

tesl

abis

anal

ysed

:the

actu

alst

ruct

ure

isde

scrib

edin

the

follo

win

gpo

int.

6.15

.1D

escr

iptio

nof

the

stru

ctur

e

The

desi

gnex

ampl

epr

opos

edin

this

sect

ion

isre

late

dto

ara

ilway

brid

gede

ckm

ade

upby

aco

ntin

uous

slab

onth

ree

span

sw

ithtw

oor

ders

ofpr

estre

ssin

gte

ndon

s(lo

ngitu

dina

land

trans

vers

epr

estre

ssin

g).T

hesl

abis

desi

gned

inca

tego

ryA

(see

Euro

code

2,Pa

rt2,

tabl

e4.

118)

forf

atig

uere

ason

s.Th

ede

ckre

sts

onab

utm

ents

and

circ

ular

pier

san

dha

saov

eral

lbr

eadt

hof

13.6

0m

with

two

side

-wal

ksof

1.40

mw

idth

,tw

oba

llast

reta

inin

gw

alls

and,

inth

em

iddl

e,tw

otra

cksp

acin

gof

5.0

m.T

hesl

abpr

esen

tsa

cons

tant

thic

knes

sof

1.50

mfo

race

ntra

lzon

e7.

0m

wid

th,w

hils

tis

tape

red

tow

ards

the

extre

mity

with

afin

alhe

ight

of0.

6m

.Fi

g.s

6.29

and

6.30

repr

esen

tth

epr

inci

pal

geom

etric

dim

ensi

onof

the

slab

brid

gean

dsu

ppor

ts�s

chem

e.

Fig

.6.2

9Pl

anvi

ewof

the

stru

ctur

ean

dsu

ppor

ts�s

chem

e

1Ex

ampl

eta

ken

from

exam

ple

7.2�s

labs�

bypr

of.

Man

cini

,FI

BBu

lletti

nn°

3,�S

truct

ural

Conc

rete

Text

book

onB

ehav

iour

,Des

ign

and

Perfo

rman

ceV

ol.3

:Dur

abili

ty-D

esig

nfo

rFire

Resis

tanc

e-M

embe

rD

esig

n-M

aint

enan

ce,A

sses

smen

tand

Rep

air-

Prac

tical

aspe

cts�

Man

ual-

text

book

(292

page

s,IS

BN

978-

2-88

394-

043-

7,D

ecem

ber1

999)

.

2Se

eto

oEN

1992

-2Eu

roco

de2,

brid

gede

sign.

Page 35: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-41

Tabl

eof

Cont

ent

Fig

.6.3

0G

eom

etric

dim

ensio

nsof

brid

gecr

osss

ectio

n

Mat

eria

lpro

pert

ies

The

follo

win

gm

ater

ials

prop

ertie

sha

vebe

enco

nsid

ered

:

Con

cret

eG

rade

35:

f ck=

35.0

MPa

;co

mpr

essi

vede

sign

stre

ngth

:f cd

=23

.3M

Pa;

com

pres

sive

resi

stan

cefo

runc

rack

edzo

nes:

f cd1

=17

.1M

Pa;

com

pres

sive

resi

stan

cefo

rcra

cked

zone

s:f cd

2=

12.0

MPa

;m

ean

valu

eof

tens

ilest

reng

th:

f ctm

=3.

23M

Pa;

mod

ulus

ofel

astic

ity:

E c=

29.7

·103

MPa

;sh

earm

odul

us:

G=

12.4

·103

MPa

Pois

son

ratio

:=

0.2

Pres

tress

ing

stee

l,(s

trand

s0.

6�):

f ptk

=18

00M

Pa;

0.1%

proo

fstre

ssf p0

.1k

=16

00M

Pato

tale

long

atio

nat

max

imum

load

:pu

>35�

mod

ulus

ofel

astic

ity:

E p=

195.

0·10

3M

Pa;

Rei

nfor

cing

stee

l,G

rade

500:

f yk=

500.

0M

Pa;

desi

gnst

reng

th:

f yd=

434.

8M

Pa;

mod

ulus

ofel

astic

ity:

E s=

200.

0·10

3M

Pa.

Con

cret

eco

ver

As

envi

ronm

enta

lcon

ditio

nan

Expo

sure

Cla

ss2

may

beco

nsid

ered

(Hum

iden

viro

nmen

tw

ithfr

ost:

exte

riorc

ompo

nent

sexp

osed

tofr

ost).

The

min

imum

conc

rete

cove

rfor

Cla

ss2

iseq

ualt

o25

mm

,whi

chsh

ould

bead

ded

toth

eto

lera

nce

valu

eof

10m

m;

asa

cons

eque

nce

the

nom

inal

valu

efo

rco

ncre

teco

ver

resu

lts:

c nom

=c m

in+

10=

25+

10=

35m

m

adop

ted

inth

eca

lcul

atio

ns.

EC2�

wor

ked

exam

ples

6-42

Tabl

eof

Cont

ent

6.15

.2St

ruct

ural

mod

el

Toev

alua

teth

ein

tern

alac

tions

onth

est

ruct

ure

alin

ear

FEM

anal

ysis

has

been

perf

orm

edad

optin

gsh

ell

elem

ents

tore

pres

ent

the

rein

forc

edsl

ab;

this

kind

ofel

emen

tta

kes

acco

unto

fall

the

slab

and

plat

eco

mpo

nent

sas

wel

las

the

out-o

f-pl

ane

shea

rfor

ces.

The

thic

knes

sof

shel

lele

men

tsha

sbe

enas

sum

edco

nsta

ntfo

rth

ein

ner

zone

ofth

esl

aban

dst

eppe

dto

fash

ion

the

tape

red

extre

mity

.In

Fig

6.31

and

6.32

the

FEM

mod

elis

sket

ched

and

the

diff

eren

tthi

ckof

the

elem

enti

srep

orte

dto

o.

Fig

.6.3

1Tr

ansv

erse

view

ofFE

Mm

odel

Fig

.6.3

2Pl

anof

FEM

mod

elan

dco

nsid

ered

elem

ents

The

adop

ted

shel

lele

men

tsar

eor

ient

edw

ithth

efo

llow

ing

guid

elin

es:

loca

laxi

s2

isor

ient

edas

glob

alax

isY

ofth

ede

ck;

loca

laxi

s3is

orie

nted

inth

eop

posi

tedi

rect

ion

ofgl

obal

axis

Xof

the

deck

;

loca

laxi

s1

isor

ient

edas

glob

alax

isZ

ofth

ede

ck.

Posi

tive

forc

esfo

rFEM

prog

ram

outp

utar

ere

porte

din

Fig.

6.33

:

Page 36: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-43

Tabl

eof

Cont

ent

Fig

.6.3

3Po

sitiv

eac

tions

forF

EMel

emen

ts

Rest

rain

ts

The

exte

rnal

rest

rain

tsha

vebe

enin

trodu

ced

inth

eFE

Mm

odel

cons

ider

ing

thei

rre

alge

omet

ricdi

men

sion

s;th

us,f

ewno

des

have

been

rest

rain

edby

mea

nsof

sprin

gel

emen

tsin

orde

rto

repr

esen

ton

lyan

indi

vidu

alre

strai

ntor

supp

ort.

Fig.

6.34

show

sa

sym

bolic

nota

tion

fort

heex

tern

alre

stra

ints

with

the

node

sinv

olve

d.

Fig

.6.3

4Ex

tern

alre

stra

ints

onth

eFE

Mm

odel

The

elas

ticco

nsta

ntof

the

sprin

gre

stra

inin

gel

emen

tsis

calc

ulat

edto

have

the

sam

est

iffne

ssof

the

subs

truct

ure

(abu

tmen

tsor

pier

s)on

whi

chth

esl

abis

rest

ed.

Fort

hex

and

ydi

rect

ions

,it

may

beas

sum

edth

atth

epi

er,o

rth

eab

utm

entf

ront

wal

l,be

have

slik

ea

EC2�

wor

ked

exam

ples

6-44

Tabl

eof

Cont

ent

sing

leco

lum

nfix

edat

the

base

and

free

athi

sto

p,so

that

the

rele

vant

Kx/

yst

iffne

ssis

valu

able

as:

KE

IH

x/y

33

whe

reE

isth

eY

oung

mod

ulus

,I

the

iner

tiaan

dH

the

heig

htof

the

colu

mn.

For

the

verti

cal

dire

ctio

n,th

ein

trins

icst

iffne

ssof

pot-b

earin

gis

assu

med

,co

nsid

erin

gth

esu

bstru

ctur

eve

rtica

lbeh

avio

uras

rigid

.

For

the

sake

ofsi

mpl

icity

the

calc

ulus

ofth

ere

leva

ntst

iffne

ssis

omitt

edan

dth

efin

alva

lues

ofth

esp

ring

cons

tant

sare

repo

rted

inta

ble

6.6

.

Loca

tion

Kx,

tot

Ky,

tot

Kz,

tot

106

kN/m

106

kN/m

106

kN/m

Abu

tmen

tA9.

5517

8.80

10.0

2Pi

erP1

4.74

11.6

1Pi

erP2

2.66

11.6

1A

butm

entB

2.78

10.0

2Ta

ble

6.6

Stiff

ness

forr

estr

aini

ngel

emen

ts

Itca

nbe

notic

edth

atth

epr

evio

usva

lues

are

refe

rred

toth

eov

eral

lst

iffne

ssof

the

rest

rain

t,th

usth

eel

astic

cons

tant

ofan

yin

divi

dual

sprin

gel

emen

tm

aybe

obta

ined

divi

ding

the

Kva

lues

ofta

ble

6.6

byth

enu

mbe

rof

elem

entr

epre

sent

ing

the

rest

rain

tor

the

supp

orts

.

Pres

tres

sing

forc

es

Two

orde

rsof

pres

tress

ing

tend

ons

are

arra

nged

(inlo

ngitu

dina

land

trans

vers

edi

rect

ions

)in

orde

rto

avoi

dan

yte

nsile

stre

ssin

conc

rete

atse

rvic

e(r

equi

red

byra

ilway

code

).Th

ein

itial

tens

ilest

ress

ofte

ndon

is:

po,m

ax=

0.85

f p0.

1k=

0.85

1600

=13

60M

Pa.

The

num

ber

ofte

ndon

sis

39fo

rth

elo

ngitu

dina

ldire

ctio

nan

d64

for

the

trans

vers

eon

e.Ea

chte

ndon

isbu

iltup

with

19st

rand

s0.

6�ha

ving

anar

eaof

1.39

cm2 .F

ig.6

.35

repo

rtste

ndon�s

layo

utfo

rhal

fdec

k,be

ing

sym

met

rical

lydi

spos

ed.

Page 37: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-45

Tabl

eof

Cont

ent

Fig

.6.3

5Pl

anan

dpr

inci

pals

ectio

nof

tend

onla

yout

Imm

edia

telo

sses

ofpr

estre

ssin

gdu

eto

fric

tion

have

been

eval

uate

dby

mea

nsof

the

follo

win

gex

pres

sion

:

po(x

)=po

,max

e-(

+k

x)

with

: =0.

19co

effic

ient

offr

ictio

nbe

twee

nth

ete

ndon

sand

thei

rshe

athi

ng;

k=

0.01

rad/

mun

inte

ntio

nala

ngul

arde

viat

ion.

Pres

tress

ing

has

tobe

intro

duce

din

the

FEM

mod

elin

orde

rto

calc

ulat

edth

ehy

pers

tatic

actio

nsth

atar

ise

inth

est

ruct

ural

sche

me.

Con

side

ring

pres

tress

ing

asan

exte

rnal

load

,iti

spo

ssib

leto

intro

duce

itby

mea

nsof

two

incl

ined

forc

esat

anch

orag

es(r

epre

sent

ing

actio

nsat

the

extre

mity

)an

dof

asy

stem

ofeq

uiva

lent

load

sal

ong

tend

on�s

prof

ile(r

epre

sent

ing

tend

oncu

rvat

ure

and

loss

esdu

eto

fric

tion)

:the

seac

tions

per

tend

on,s

houl

dbe

appl

ied

cons

iste

ntly

atth

eno

deso

fFEM

mod

el.

The

equi

vale

ntlo

ads

may

beca

lcul

ated

subd

ivid

ing

the

tend

onpr

ofile

into

elem

enta

ryse

gmen

tsan

dev

alua

ting

the

inte

rnal

actio

nab

leto

equi

libra

teth

eex

tern

alon

edu

eto

end

actio

nsde

rivin

gby

the

pres

tress

ing.

EC2�

wor

ked

exam

ples

6-46

Tabl

eof

Cont

ent

Fig

.6.3

6Ef

fect

ofpr

estr

essi

ngon

ase

gmen

tand

equi

vale

ntlo

ads

Fig.

6.36

repr

esen

tsth

efo

rces

actin

gon

ase

gmen

tof

conc

rete

due

toa

curv

edpr

estre

ssin

gte

ndon

;ift

hein

clin

atio

nof

the

cabl

ech

ange

sfr

om1

to2

whi

leth

epr

estre

ssfo

rce

chan

ges

from

P 1to

P 2du

eto

fric

tion,

the

equi

libra

ting

verti

cala

ndho

rizon

talf

orce

sin

the

i-seg

men

tres

ult:

F v,i

=P 2

sin

2P 1

sin

1;

F h,i

=P 2

cos

2P 1

cos

1

whi

leth

eba

lanc

ing

mom

entt

urns

out:

Mi=

(P2

cos

2e 2

P 1co

s1

e 1)

(P2

sin

2P 1

sin

1)a

/2

The

abov

epr

oced

ure

shou

ldbe

repe

ated

for

all

the

segm

ents

.It

can

beno

tice

that

the

forc

esat

the

end

ofea

chse

gmen

text

rem

ityar

eth

esa

me

with

oppo

site

sign

s,de

pend

ing

onw

heth

erth

erig

htor

the

left

segm

enti

sco

nsid

ered

;the

sefo

rces

canc

elou

tthe

mse

lves

with

the

exce

ptio

nat

anch

orag

es.F

inal

ly,f

orea

chte

ndon

,th

efo

rces

atth

eex

trem

ityof

the

cabl

epl

usth

eeq

uilib

ratin

gsy

stem

for

each

segm

ent,

shal

lbe

intro

duce

din

the

FEM

mod

el.

The

choi

ceof

the

posi

tion

ofth

eel

emen

tary

segm

ents

isre

lativ

eto

the

kind

ofel

emen

tad

opte

din

the

FEM

mod

el.I

fbe

amel

emen

tsar

eus

ed,i

tis

poss

ible

toin

trodu

cea

poin

tlo

ad(o

rm

omen

t)w

heth

eral

ong

the

elem

entb

ody

orat

node

s,co

nseq

uent

lyth

ese

gmen

tex

trem

ities

may

bepl

aced

indi

ffer

ently

atno

des

orat

the

mid

dle

ofth

eel

emen

t.W

ithsh

ell

elem

ents

,on

lyno

dal

forc

esca

nbe

cons

ider

edso

that

itis

nece

ssar

yto

plac

ese

gmen

tex

trem

ities

with

intw

ose

quen

tialn

odes

;fur

ther

mor

e,du

eto

the

two-

dim

ensi

onal

sche

me,

one

has

toco

nsid

erth

etra

nsve

rse

posi

tion

ofth

ete

ndon

that

,in

gene

ral,

dono

tcoi

ncid

ew

itha

noda

lalig

nmen

t.A

sa

sim

ple

rule

,the

indi

catio

nsof

Fig.

6.37

may

befo

llow

ed.

Page 38: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-47

Tabl

eof

Cont

ent

Fig

.6.3

7Tr

ansv

erse

distr

ibut

ion

ofpr

estre

ssin

g

Tim

e-de

pend

entp

rest

ress

ing

loss

es

Tim

e-de

pend

entl

osse

sof

pres

tress

may

beev

alua

ted

bym

eans

ofth

efo

llow

ing

equa

tion:

pc

sr

css

prcg

cp

p c

c ccp

tt

Et

tA A

A Iz

tt

,

(,

)(

,)(

)

.(

,)

00

0

20

11

10

8

whe

re:

p,c+

s+r:

loss

ofin

itial

tend

onst

ress

due

tocr

eep

and

shrin

kage

ofco

ncre

tean

dre

laxa

tion

ofst

eel,

betw

een

time

t 0an

dtim

et

;

t 0=

28da

ys:

age

ofco

ncre

teat

pres

tress

ing

time;

t=

2555

0ds

.:co

rres

pond

ing

toa

life-

time

of70

year

s;

cs(t

,t 0):

shrin

kage

stra

inat

time

tca

lcul

ated

from

:cs

(t,t 0

)=cs

0s(

t-t

0)=

0.12

710

-3

whe

re:

cso

=s

(fcm

)RH

with

:

s(f

cm)=

[160

+10

sc(9

f cm/f c

mo)

]10

-6=

0.00

0395

f cm=

mea

nco

mpr

essi

vest

reng

htof

conc

rete

at28

days

=f ck

+8

MPa

;

f cmo

=10

MPa

;

sc=

5fo

rrap

idha

rden

ing

cem

ents

;

RH=

155

110

0

3

.R

H=

1.01

8;

RH

=70

%re

lativ

ehu

mid

ityof

the

ambi

enta

tmos

pher

e;

s(t

-t0)

=t

th

tt

02

00

035

.=

0.57

4

EC2�

wor

ked

exam

ples

6-48

Tabl

eof

Cont

ent

h=

(2A

c/u

)=12

17m

mno

tiona

lsiz

eof

mem

ber;

Ac

=17

.43

106

mm

2gr

osss

ectio

nof

the

beam

;

u=

2864

0m

mpe

rimet

erof

the

mem

beri

nco

ntac

twith

the

atm

osph

ere;

(t,t 0

):cr

eep

coef

ficie

ntat

time

tca

lcul

ated

from

:(t

,t 0)=

0c(t

-t0)

=1.

5708

whe

re:

o=

RH(f

cm)

(t 0)=

1.59

8w

ith

RH=

11

100

013

RH

h.

=1.

281;

(fcm

)=53. f

fcm

cmo

=2.

556;

(t 0)=

101

002

..

t=

0.48

8

c(t

-t0)

=t

tt

tH

0

0

03.

=0.

983

with

H=

151

001

225

018

..

RH

h=

2155

>15

0015

00

Ifth

eim

prov

edpr

edic

tion

mod

elof

chap

ter

3is

used

,the

follo

win

gva

lues

for

cs(t

,t0)

and

for

(t,t

0)m

aybe

eval

uate

d:

cs(t

,t0)

=18

2.62

10-6

;(t

,t0)

=1.

5754

ingo

odag

grem

entw

ithth

epr

evio

uson

e,at

leas

tfor

cree

pva

lue.

pr:

loss

ofpr

estre

ssin

gdu

eto

rela

xatio

nof

stee

lcal

cula

ted

for

are

duce

din

itial

tens

ilest

ress

ofp

=pg

o0.

3p,

c+s+

r(w

here

pgo

isth

eef

fect

ive

initi

alst

ress

inte

ndon

sdu

eto

dead

load

and

pres

tress

ing)

and

eval

uate

das

perc

enta

geby

the

follo

win

gfo

rmul

a:

t=

1000

ht

1000

019.

=10

00h

3w

here

t=is

the

rela

xatio

naf

tert

hour

s;fo

rt>

50ye

ars

t.=

1000

h3;

1000

h=

isth

ere

laxa

tion

afte

r100

0ho

urse

valu

ated

from

Fig.

6.38

;

Page 39: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-49

Tabl

eof

Cont

ent

Fig

.6.3

8Re

laxa

tion

loss

esin

%at

1000

hour

sfor

Cla

ss2

c.:

stre

sson

conc

rete

atle

velo

fpre

tens

ione

dst

eeld

ueto

self

wei

ghta

ndpe

rman

entl

oad;

cpo

:st

ress

onco

ncre

teat

leve

lofp

rete

nsio

ned

stee

ldue

topr

estre

ssin

g;

=E s

/Ec:

mod

ulus

ofel

astic

ityra

tio;

Ap

:ar

eaof

pres

tress

ing

stee

latt

heco

nsid

ered

leve

l;

Ac

:ar

eaof

conc

rete

gros

sse

ctio

n;

I c:

iner

tiaof

conc

rete

gros

ssec

tion;

z cp

:le

vera

rmbe

twee

nce

ntro

idof

conc

rete

gros

ssec

tion

and

pres

tress

ing

stee

l.

Tim

e-de

pend

entl

osse

sof

pres

tress

ing

shou

ldbe

calc

ulat

edfo

rea

chte

ndon

alon

ghi

spr

ofile

soth

ata

corr

ectv

alue

may

beus

edfo

reac

hel

emen

t.A

sa

refe

renc

e,th

em

axim

umva

lue

ofpr

estre

ssin

glo

sses

,asp

erce

ntag

eof

initi

alst

eelt

ensi

on,t

urn

out:

long

itudi

nalt

endo

n:19

%at

anch

orag

ean

d14

%at

pier

axis

;

trans

vers

ete

ndon

:18

%at

anch

orag

ean

d12

%at

mid

span

.

The

effe

cts

oflo

sses

are

take

nin

toac

coun

tw

ithth

esa

me

proc

edur

eus

edfo

rth

epr

estre

ssin

g,bu

tasa

ctio

nsof

oppo

site

sign

.

6.15

.2A

ctio

ns

The

exte

rnal

load

sap

plie

don

the

stru

ctur

esh

ould

beev

alua

ted

acco

rdin

gto

the

prov

isio

nsof

Euro

code

1.3

Traf

ficLo

adon

Brid

ges.

As

verti

calt

rain

load

the

load

mod

elLM

71pl

usth

elo

adm

odel

sSW

(SW

/0an

dSW

/2re

spec

tivel

y)ha

vebe

enad

opte

dw

ithan

coef

ficie

ntof

1.1.

For

the

LM71

,th

e4

poin

tlo

ads

have

been

redu

ced

inan

equi

vale

ntun

iform

load

bysm

earin

gth

eirc

hara

cter

istic

valu

eQ

vkal

ong

the

influ

ence

leng

thso

that

aq v

k,1

may

beob

tain

ed:

Qvk

=1.

125

0di

n=

319.

6kN

q vk,

1=

319.

6/1.

6=

199.

75kN

/m

EC2�

wor

ked

exam

ples

6-50

Tabl

eof

Cont

ent

whe

redi

n,b

eing

the

dyna

mic

fact

oreq

ualt

o1.

162,

isev

alua

ted

belo

w.

Fig

.6.3

9Ad

opte

dlo

adar

rang

emen

tfor

LM71

load

mod

el

The

unifo

rmly

dist

ribut

edlo

adq v

kac

cord

ing

toEu

roco

de1.

3is

:

q vk

=1.

180

din

q vk,

2=

102.

3kN

/m

with

outa

nylim

itatio

nin

leng

th.

Fig.

6.39

show

sth

eLM

71ar

rang

emen

tad

opte

din

the

calc

ulat

ions

.

The

load

mod

elSW

/0is

repr

esen

ted

inFi

g.6.

40an

dits

char

acte

ristic

valu

ere

sults

:

q vk

=1.

113

3di

n=

170.

0kN

/m

Fig

.6.4

0Lo

adm

odel

SW/0

The

load

mod

elSW

/2is

repr

esen

ted

inFi

g.6.

41an

dits

char

acte

ristic

valu

ere

sults

:

q vk

=1.

115

0di

n=

174.

3kN

/m

Fig

.6.4

1Lo

adm

odel

SW/2

The

prev

ious

load

mod

elLM

71,S

W/0

and

SW/2

have

been

intro

duce

din

the

FEM

anal

ysis

cons

ider

ing

asp

read

ing

ratio

of4:

1in

the

balla

stan

dof

1:1

inth

eco

ncre

teup

toth

em

iddl

epl

ane

ofth

esl

ab.

Inth

efo

llow

ing

asle

fttra

ckis

deno

ted

the

track

whi

chha

sa

posi

tive

valu

efo

rthe

yco

-ord

inat

e,w

hile

right

truck

the

othe

rone

.Fi

g.6.

42sh

ows

whi

chel

emen

tsar

ein

volv

edby

spre

adin

gef

fect

s,th

eref

ore

subj

ecte

dto

varia

ble

load

.

Page 40: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-51

Tabl

eof

Cont

ent

Fig

.6.4

2Sp

read

ing

effe

ctso

nFE

Mm

odel

and

load

edel

emen

ts

The

dyna

mic

fact

oris

calc

ulat

edby

mea

nsof

the

follo

win

gex

pres

sion

(trac

kw

ithst

anda

rdm

aint

enan

ce):

0.73

0.2

L2.16

31.

162

whe

reL

isth

ede

term

inan

tlen

gth

defin

edin

the

Euro

code

1.3

as:

LL

LL

133

1317

3327

7517

333

2704

12

3.

..

..

.m

Seve

ralo

ther

actio

ns,a

risin

gfr

omva

riabl

elo

ads,

shou

ldbe

cons

ider

edin

the

anal

ysis

(as

tract

ion

and

brak

ing,

cent

rifug

alfo

rces

,de

railm

ent,

win

dpr

essu

re,

diff

eren

tial

tem

pera

ture

varia

tion

etc.

)bu

t,fo

rth

esa

keof

sim

plic

ity,i

nth

ese

calc

ulat

ions

only

the

follo

win

gac

tions

have

been

cons

ider

ed(in

trodu

ced

inth

em

athe

mat

ical

mod

elin

diff

eren

tst

eps)

:

STEP

1:Se

lf-w

eigh

toft

hest

ruct

ure:

adop

ting

aun

itw

eigh

t3 ;

STEP

2:Pr

estre

ssin

gfo

rces

attim

eof

tens

ioni

ng;

STEP

3:Pr

estre

ssin

gfo

rces

afte

rtim

e-de

pend

entl

osse

s:

inth

eca

lcul

atio

ns,a

limit

valu

eof

tens

ilest

ress

inte

ndon

equa

lto

0.6

f ptk

afte

ral

low

ance

for

loss

es(t

),ha

sbe

enco

nsid

ered

,ac

cord

ing

toth

epr

ovis

ions

ofth

eap

plie

dR

ailw

ayC

ode

toav

oid

the

risk

ofbr

ittle

failu

redu

eto

stre

ssco

rros

ion.

STEP

4:Tr

ack

load

com

preh

ensi

veof

;

rails

,sle

eper

san

dba

llast

(wat

erpr

oofin

gin

clud

ed)

eval

uate

das

aco

ver

with

ano

min

alhe

ight

of0.

8m

and

aun

itw

eigh

tof

=18

kN/m

3 ),so

that

fora

wid

thof

9.5

m,a

nun

iform

lydi

strib

uted

load

resu

lts:

g bal

last

=0.

81.

89.

5=

136.

8kN

/m;

STEP

5:O

ther

spe

rman

entl

oads

com

pose

dby

;

trans

vers

egr

adie

ntfo

rdr

ain

wat

er,a

ssum

edas

alo

adof

1.25

kN/m

2it

turn

sou

t:

EC2�

wor

ked

exam

ples

6-52

Tabl

eof

Cont

ent

g dra

in=

1.25

9.5

=11

.875

kN/m

;

balla

stre

tain

ing

wal

ls(w

itha

cros

sse

ctio

nar

eaof

0.25

m2

and

unit

wei

ghto

f25

kN/m

3 ) g wal

ls=

250.

25=

6.25

kN/m

fore

ach;

duct

s:

g duc

ts=

3kN

/mfo

reac

h;

bord

ercu

rbs

(with

acr

oss

sect

ion

area

of0.

1m

2an

dun

itw

eigh

tof

25kN

/m3 ): g r

einf

beam

=25

0.25

=6.

25kN

/mfo

reac

h;

nois

eba

rrie

rs:

g bar

riers

=8.

00kN

/mfo

reac

h;

STEP

6:V

aria

ble

load

sfo

rmax

imum

bend

ing

mom

ento

nfir

stsp

an(x

=6.

18m

);

the

appl

ied

load

isa

LM71

mod

elon

the

left

track

with

the

follo

win

glo

ngitu

dina

larr

ange

men

t:

Fig

.6.4

3LM

71ar

rang

emen

tfor

Load

Step

5

plus

aSW

/2tra

inon

the

right

track

with

the

follo

win

glo

ngitu

dina

lar

rang

emen

t:

Fig

.6.4

4SW

/2ar

rang

emen

tfor

Load

Step

5

STEP

7:V

aria

ble

load

sfo

rmin

imum

bend

ing

mom

enta

tpie

rP1

(x=

18.4

3m

);

the

appl

ied

load

isa

SW/0

mod

elon

the

left

track

with

the

follo

win

glo

ngitu

dina

larr

ange

men

t:

Page 41: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-53

Tabl

eof

Cont

ent

Fig

.6.4

5SW

/0ar

rang

emen

tfor

Load

Step

6

plus

aSW

/2tra

inon

the

right

track

with

the

follo

win

glo

ngitu

dina

lar

rang

emen

t:

Fig

.6.4

6SW

/2ar

rang

emen

tfor

Load

Step

6

STEP

8:V

aria

ble

load

sfo

rmax

bend

ing

mom

ento

nse

cond

span

(x=

32.3

05m

);

the

appl

ied

load

isa

LM71

mod

elon

the

left

track

with

the

follo

win

glo

ngitu

dina

larr

ange

men

t:

Fig

.6.4

7LM

71ar

rang

emen

tfor

Load

Step

7

plus

aSW

/2tra

inon

the

right

track

with

the

follo

win

glo

ngitu

dina

lar

rang

emen

t:

Fig

.6.4

8SW

/2ar

rang

emen

tfor

Load

Step

7

EC2�

wor

ked

exam

ples

6-54

Tabl

eof

Cont

ent

6.15

.3C

ombi

natio

nsof

Act

ions

The

desi

gnva

lues

fort

heex

tern

alac

tions

have

been

calc

ulat

edad

optin

gth

eco

mbi

natio

nsof

load

sspe

cifie

din

the

appl

ied

Cod

eas

follo

win

dica

ted

inth

esy

mbo

licpr

esen

tatio

n:

Ulti

mat

eLi

mit

Stat

e

SS

dG

kG

kp

kQ

koi

iki

GG

PQ

Q1

12

21

1

Serv

icea

bilit

yLi

mit

Stat

e:ra

reco

mbi

natio

n

SS

dG

GP

QQ

kk

kk

oiik

i1

21

1

Serv

icea

bilit

yLi

mit

Stat

e:qu

asi-p

erm

anen

tcom

bina

tion

SS

dG

GP

Qk

kk

iik

i1

22

1

whe

re:

G1k

=ch

arac

teris

ticva

lue

ofth

eac

tion

due

tose

lf-w

eigh

tand

perm

anen

tloa

ds,b

alla

stex

clud

ed;

G2k

=ch

arac

teris

ticva

lue

ofac

tion

due

toba

llast

self-

wei

ght;

P k=

char

acte

ristic

valu

eof

actio

ndu

eto

pres

tress

;

Q1k

=ch

arac

teris

ticva

lue

ofac

tion

due

toth

eba

seva

riabl

eac

tion;

Qik

=ch

arac

teris

ticva

lue

actio

ndu

eto

ofth

eot

heri

ndep

ende

ntva

riabl

elo

ads;

1=

parti

alfa

ctor

ofse

lf-w

eigh

tan

dpe

rman

ent

load

s,ba

llast

excl

uded

,equ

alto

1.4

foru

nfav

oura

ble

effe

ctan

d1.

0fo

rfav

oura

ble

effe

ct;

2=

parti

alfa

ctor

ofba

llast

load

equa

lto

1.8

for

unfa

vour

able

effe

ctan

d1.

0fo

rfa

vour

able

effe

ct;

P=

parti

alfa

ctor

ofpr

estre

sslo

adeq

ual

to1.

2fo

run

favo

urab

leef

fect

and

0.9

for

favo

urab

leef

fect

;

Q=

parti

alfa

ctor

ofva

riabl

elo

ads

equa

lto

1.5

for

unfa

vour

able

effe

ctan

d0.

0fo

rfa

vour

able

effe

ct;

0i=

com

bina

tion

fact

orof

varia

ble

load

sequ

alto

0.8;

2i=

com

bina

tion

fact

orof

varia

ble

load

sfo

rqu

asi-p

erm

anen

tcom

bina

tion

atse

rvic

e,eq

ualt

o0.

6.

Page 42: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-55

Tabl

eof

Cont

ent

6.15

.4V

erifi

catio

nat

Serv

icea

bilit

yL

imit

Stat

e

The

verif

icat

ion

atse

rvic

eabi

lity

limit

stat

eis

rela

tive

toth

efo

llow

ing

cond

ition

s:

stre

sslim

itatio

nat

tens

ioni

ng;

stre

sslim

itatio

nat

serv

ice;

crac

kw

idth

s;

defo

rmat

ion.

Veri

ficat

ion

atte

nsio

ning

Att

ime

ofte

nsio

ning

,no

tens

ilest

ress

shou

ldbe

pres

enti

nth

eex

trem

efib

res

ofth

esl

aban

dth

em

axim

umco

mpr

essi

vest

ress

shou

ldno

texc

eed

the

limit

valu

eof

0.6

f ck=

21M

Pa.

For

the

sake

ofsi

mpl

icity

,one

repo

rtsth

eve

rific

atio

nre

late

dto

the

four

elem

ents

show

edin

figii,

assu

bjec

ted

toth

ehi

gher

stre

ssle

vel.

The

exte

rnal

actio

nsar

eca

lcul

ated

adop

ting

the

rare

com

bina

tion

with

only

the

load

step

s1

and

2.Fr

omFE

Man

alys

is,t

heva

lue

ofn 2

2,m

22,n

33,m

33,n

23,m

23ar

eev

alua

ted

soth

atit

resu

lts:

yt

th

h,

,22

2222 2

6n

m;

yb

bh

h,

,22

2222 2

6n

m

xt

th

h,

,33

3333 2

6n

m;

xb

bh

h,

,33

3333 2

6n

m

xyt

th

h,

,23

2323 2

6n

m;

xyb

bh

h,

,23

2323 2

6n

m

whe

reth

esu

bscr

ipts

tan

db

indi

cate

resp

ectiv

ely

top

and

botto

mfib

re.

The

angl

esof

prin

cipa

ldire

ctio

ns(f

orw

hich

isxy

=0)

are:

123

2233

1 22

atan

;2

=1

+90

°

and

the

prin

cipa

lstre

sses

resu

lt:

122

21

332

123

12

,/

,/

,/

,/

cos

()

()

()

tb

tb

tb

tb

sin

sin

222

22

332

223

22

,/

,/

,/

,/

cos

()

()

()

tb

tb

tb

tb

sin

sin

Refe

rring

toth

eel

emen

tsm

arke

din

Fig.

6.32

one

obta

ins:

Tabl

e6.

7

Elem

.h

n22

n33

n23

m22

m33

m23

[m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

m/m

][k

Nm

/m]

[kN

m/m

]

648

1.5

-309

1-1

3159

6-2

25-2

176

093

0.96

3-7

806

-852

675

743

456

-51

320

1.5

-351

6-1

0418

1-4

5-8

120

589

1.5

-428

0-1

0007

-67

653

1945

20

Tabl

e6.

8

EC2�

wor

ked

exam

ples

6-56

Tabl

eof

Cont

ent

22,b

33,b

23,b

22,t

33,t

23,t

1,b

2,b

1,t

2,t

1,b

2,b

1,t

2,t

[Mpa

][M

pa]

[Mpa

][M

pa]

[Mpa

][M

pa]

[°]

[°]

[°]

[°]

[Mpa

][M

pa]

[Mpa

][M

pa]

-2.6

6-1

4.58

0.00

-1.4

6-2

.97

0.00

0.02

89.9

80.

1589

.85

-2.6

6-1

4.58

-1.4

6-2

.97

-3.3

0-5

.90

-0.2

5-1

2.91

-11.

800.

41-5

.48

95.4

8-1

8.17

108.

17-3

.27

-5.8

3-1

3.05

-12.

15-2

.46

-9.1

10.

00-2

.22

-4.7

80.

000.

0189

.99

0.01

89.9

9-2

.46

-9.1

1-2

.22

-4.7

8-1

.11

-1.4

80.

01-4

.59

-11.

86-0

.10

1.29

88.7

1-0

.77

90.7

7-1

.11

-1.4

8-4

.59

-11.

85

whi

chno

texc

eed

the

limit

one.

Veri

ficat

ion

oflim

itst

ate

ofst

ress

limita

tion

inco

ncre

te

The

serv

icea

bilit

ylim

itsta

tes

chec

ked

inth

isse

ctio

nar

ere

lativ

eon

lyto

stre

sslim

itatio

n,en

surin

gth

at,u

nder

serv

ice

load

cond

ition

s,co

ncre

teex

trem

estr

esse

sdo

note

xcee

dth

eco

rresp

ondi

nglim

it,fo

rthe

quas

i-per

man

enta

ndth

era

reco

mbi

natio

ns.T

helim

itst

ress

esfo

rcon

cret

ear

e:

Qua

si-pe

rman

entc

ombi

natio

n:C

ompr

essiv

est

ress

=0.

4f ck

=14

.00

MPa

Rare

com

bina

tion:

Com

pres

sive

stre

ss=

0.6

f ck=

21.0

0M

PaA

pply

ing

toth

estr

uctu

ral

FEM

mod

elth

eva

riabl

elo

ads

and

com

bini

ngth

emac

cord

ing

toth

era

ilway

code

prov

ision

s,on

eob

tain

the

max

ima

stres

sva

lues

atto

pan

dbo

ttom

fibre

sth

atha

veto

belo

wer

than

the

corre

spon

ding

limit.

One

repo

rtsth

ere

sults

rela

tive

toth

efo

urel

emen

tsin

dica

ted

inFi

g.6.

32.

Qua

si-P

erm

anen

tCom

bina

tion

Tabl

e6.

9

Elem

.h

n22

n33

n23

m22

m33

m23

[m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

m/m

][k

Nm

/m]

[kN

m/m

]

648

1.5

-242

0-1

0152

4-2

36-1

576

493

0.96

3-6

233

-634

750

589

108

-37

320

1.5

-353

9-7

855

281

233

458

91.

5-2

736

-790

0-3

-151

-396

0

1,b

2,b

1,t

2,t

[Mpa

][M

pa]

[Mpa

][M

pa]

-2.2

4-1

0.97

-0.9

8-2

.57

-2.6

5-5

.86

-10.

31-7

.37

-2.1

4-4

.62

-2.5

8-5

.86

-2.2

3-6

.32

-1.4

2-4

.21

Rare

Com

bina

tion

Tabl

e6.

10

Elem

.h

n22

n33

n23

m22

m33

m23

[m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

m/m

][k

Nm

/m]

[kN

m/m

]

648

1.5

-223

8-1

0270

3-2

26-6

154

930.

963

-628

4-6

033

457

7-1

33-6

232

01.

5-2

604

-747

97

712

79-9

589

1.5

-379

1-8

243

-55

-689

-127

5-2

6

1,b

2,b

1,t

2,t

[Mpa

][M

pa]

[Mpa

][M

pa]

-2.0

9-8

.49

-0.8

9-5

.21

-2.7

6-7

.02

-10.

29-5

.51

-1.7

2-1

.58

-1.7

5-8

.40

-4.3

6-8

.89

-0.6

9-2

.09

Veri

ficat

ion

ofSe

rvic

eabi

lity

Lim

itSt

ate

ofC

rack

ing

The

char

acte

ristic

crac

kw

idth

shou

ldbe

calc

ulat

edac

cord

ing

toth

epr

ovisi

ons

ofM

odel

Page 43: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-57

Tabl

eof

Cont

ent

Code

90.

Itha

sbe

notic

e,ho

wev

er,t

hat

from

stres

sca

lcul

atio

nne

ither

for

the

quas

i-pe

rman

entc

ombi

natio

nno

rin

the

rare

one,

the

max

imum

stres

sre

sults

tens

ile.T

here

fore

,no

spec

ific

rein

forc

emen

tisr

equi

red

and

itis

suffi

cien

tto

arra

nge

the

min

imum

amou

ntof

rein

forc

ing

steel

,abl

eto

ensu

rea

duct

ilebe

havi

our

inca

seof

corro

sion

ofpr

estre

ssin

gste

el.

Def

orm

atio

n

Def

orm

atio

nlim

itatio

nis

carr

ied

out

toco

ntro

lth

em

axim

umve

rtica

lde

flect

ion

for

pass

enge

rsco

mfo

rt.Th

elim

itva

lues

/L(d

efle

ctio

n/sp

anLe

ngth

)ar

egi

ven

byth

eEu

roco

de1.

3as

afu

nctio

nof

the

span

leng

than

dth

etra

insp

eed.

The

limit

valu

efo

rm

axim

umve

rtica

ldef

lect

ion

isca

lcul

ated

cons

ider

ing

asp

anle

ngth

of27

.75

m(c

entra

lsp

an)a

nda

train

spee

dov

er28

0km

/h;a

ccor

ding

toth

epr

ovisi

onso

fthe

Code

,itr

esul

ts:

L1

1600

that

shou

ldbe

mul

tiplie

dby

afa

ctor

1.1

for

cont

inuo

usstr

uctu

res;

final

ly,t

hefo

llow

ing

limit

may

beac

hiev

ed:

lim.

L11 1600

114

55

As

aco

nseq

uenc

eof

the

trans

ient

natu

reof

this

even

t,th

eel

astic

defle

ctio

n,ca

lcul

ated

byth

eFE

Mm

odel

,is

rela

tive

toth

eon

lyliv

elo

ad;t

hech

eck

shal

lbe

perfo

rmed

load

ing

only

one

track

,re

adin

gth

em

axim

umde

flect

ion

inco

rresp

onde

nce

ofth

etra

ckax

is.H

avin

glo

aded

the

right

track

with

aLM

71lo

adm

odel

plus

dyna

mic

allo

wan

ce,p

lace

din

the

mid

dle

ofth

eof

the

cent

rals

pan,

the

obta

ined

/Lva

lue

is:

effe

ctiv

e

L0

0055

2775

150

45.

.

and

itre

sults

low

erth

anth

eco

rresp

ondi

nglim

it.

Itca

nbe

notic

eth

atno

furth

erca

lcul

atio

nis

requ

este

dbe

caus

e,du

eto

pres

tress

ing

effe

ct,t

hest

ruct

ure

rem

ains

entir

ely

com

pres

sed,

soth

atth

eel

astic

valu

e,ca

lcul

ated

byth

eFE

Man

alys

is,ha

sto

beco

nsid

ered

.

6.15

.5V

erifi

catio

nof

Ulti

mat

eL

imit

Stat

e

Ver

ifica

tion

atU

LSsh

ould

rega

rdth

est

ruct

ure

asa

who

lean

dits

com

pone

ntpa

rts,

anal

ysin

gth

ere

sista

nce

ofth

ecr

itica

lre

gion

s.In

addi

tion

toth

ean

alys

isof

ULS

ofse

vera

lshe

llel

emen

tund

erth

ere

leva

ntco

mbi

natio

nof

inte

rnal

actio

ns,i

nth

isex

ampl

eso

me

case

ofde

taili

ngar

ein

vesti

gate

d,i.e

.:

burs

ting

forc

eat

anch

orag

eof

pres

tress

ing

tend

on;

spal

ling

forc

eat

anch

orag

eof

pres

tress

ing

tend

on;

punc

hing

unde

rsup

port

plat

e.

EC2�

wor

ked

exam

ples

6-58

Tabl

eof

Cont

ent

Slab

ultim

ate

limit

stat

e

Ver

ifica

tion

atU

LSha

sbe

enpe

rform

edad

optin

gth

esa

ndw

ich

mod

elfo

rshe

llel

emen

ts.

The

inte

rnal

actio

nsin

ash

elle

lem

enta

tULS

are

sket

ched

inFi

g.6.

49.

Fig

.649

Inte

rnal

actio

nsat

ULS

ina

shel

lele

men

ts

Let

usco

nsid

erin

this

sect

ion

only

four

elem

ents

onth

ew

hole

(see

Fig.

6.32

).Th

eex

tern

alac

tions

are

deriv

edfr

omFE

Mm

odel

usin

gth

elo

adst

epfo

rtra

ins

whi

chle

ads

toth

em

axim

umva

lues

and

com

bini

ngth

ere

sults

acco

rdin

gto

the

rele

vant

com

bina

tion

form

ula.

Fort

hein

vesti

gate

del

emen

ts,tu

rnso

ut(o

nbr

acke

tsth

eno

tatio

nof

Fig.

6.49

):Ta

ble

6.11

Elem

.h

nSd

,yn

Sd,x

nSd

,xy

mSd

,ym

Sd,x

mSd

,xy

v Sd,

yv S

d,x

(n22

)(n

33)

(n23

)(m

22)

(m33

)(m

23)

(v13

)(v

12)

[m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

m/m

][k

Nm

/m]

[kN

m/m

][k

N/m

][k

N/m

]

648

1.5

-177

9-9

096

5-2

3947

0-1

4-6

-593

0.96

3-5

746

-461

0-6

349

9-6

71-7

589

-150

320

1.5

-213

0-5

922

1038

3241

-13

2047

589

1.5

-386

5-7

748

-54

-195

0-4

274

-41

-112

4-1

095

Asf

irsts

tep,

one

may

desig

nth

ein

nerl

ayer

chec

king

ifsp

ecifi

csh

earr

einf

orce

men

tis

requ

ired

orno

t.In

fact

,iti

spos

sible

toca

lcul

ate

the

prin

cipa

lshe

arv o

2=

v x2

+v y

2,o

nth

epr

inci

pals

hear

dire

ctio

no

(suc

hth

atta

n0

vv

yx

),an

dto

chec

kth

atit

turn

out:

v<

v0

11

301

210

0R

dckf

d.

whe

rev R

d1is

spec

ified

inch

apte

r6.4

.2.3

ofM

C90

and

xo

yo

sin

cos2

2.

Ifth

eis

nots

atisf

ied,

spec

ific

shea

rrei

nfor

cem

ents

hall

bear

rang

ed(v

ertic

alst

irrup

s)an

ddi

agon

alco

mpr

essiv

efo

rces

inco

ncre

tesh

all

bech

ecke

d.A

ccor

ding

toCE

BBu

lletin

223,

and

havi

ngse

tam

inim

umam

ount

oflo

ngitu

dina

land

trans

vers

ere

info

rcem

enti

nth

ebo

ttom

and

top

laye

rof

As,x

=A

s,y=

22.6

cm2 /m

plac

edat

0.07

mfro

mth

eex

tern

alfa

ce,t

hefo

llow

ing

tabl

em

aybe

calc

ulat

edfo

rthe

elem

ents

cons

ider

ed.

Tabl

e6.

12

Page 44: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-59

Tabl

eof

Cont

ent

Elem

.d

oo

v ov R

d1F

Scw

FR

cwA

s/s2

nxc

nyc

nxy

c

[m]

[°]

[-][k

N/m

][kN

/m]

[°]

[kN

/m]

[kN

/m]

[cm

2 /m2 ]

[kN

/m]

[kN

/m]

[kN

/m]

648

1.43

51.1

80.

0015

87

417

26.5

6-

--

0.0

0.0

0.0

930.

893

-30.

770.

0025

317

432

726

.56

--

-0.

00.

00.

032

01.

4323

.14

0.00

158

5141

726

.56

--

-0.

00.

00.

058

91.

4345

.76

0.00

158

1569

417

26.5

635

0913

860

14.0

763.

980

5.6

784.

5

with

varia

tion

ofsl

abco

mpo

nent

sdue

tov x

and

v y(i.

e.n x

c,n

ycan

dn x

yc)o

nly

fore

lem

ent

num

ber5

89.

The

oute

rlay

ers

shou

ldbe

desig

ned

supp

osin

gan

initi

alth

ickn

ess

forb

oth

laye

rsno

tle

sser

than

twic

eth

eco

ncre

teco

ver

eval

uate

dat

the

cent

roid

ofre

info

rcem

ent.

One

assu

mes

:

t s=

t i=

20.

07=

0.14

mso

that

,int

erna

llev

erar

mz

and

inpl

ane

actio

nsm

aybe

eval

uate

dfo

rthe

oute

rlay

ers

ofea

chel

emen

tref

errin

gto

Fig.

6.50

and

bym

eans

ofth

efo

llow

ing

equa

tions

:

Fig

.6.5

0In

tern

alfo

rces

inth

edi

ffere

ntla

yers

nn

zy z

m zv v

Sdx

sx

sx

,co

t1 2

x2 0

nn

zy z

m zv v

Sdx

ix

ix

,co

t1 2

x2 0

nn

zy z

m zv v

Sdy

sy

sy

,co

t1 2

y2 0

nn

zy z

m zv v

Sdy

iy

iy

,co

t1 2

y2 0

vx

y

0Sd

sxy

sxy

nz

y zm z

vv v

,co

t1 2

vx

y

0Sd

ixy

ixy

nz

y zm z

vv v

,co

t1 2

whe

rete

rms

onbr

acke

tsha

vebe

sum

med

ifsh

earr

einf

orce

men

tis

requ

ired.

Inth

ede

sign

EC2�

wor

ked

exam

ples

6-60

Tabl

eof

Cont

ent

proc

edur

eis

conv

enie

ntto

reac

hth

em

inim

umam

ount

ofre

info

rcem

ent,

soth

ata

valu

eof

45°f

oran

gle

may

bead

opte

d.Fo

rthe

chos

enel

emen

tsit

turn

sout

:Ta

ble

6.13

Elem

.h

t st i

t cy s

y iz

nSd

y,s

nSd

x,s

v Sd,

sn

Sdy,

in

Sdx,

iv S

d,i

[m]

[m]

[m]

[m]

[m]

[m]

[m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

/m]

648

1.5

0.14

00.

140

1.22

00.

680

0.68

01.

360

-713

.5-4

893.

313

.0-1

065.

1-4

202.

2-7

.793

0.96

30.

140

0.14

00.

683

0.41

20.

412

0.82

3-3

479.

6-1

489.

859

.3-2

266.

7-3

120.

5-1

22.3

320

1.5

0.14

00.

140

1.22

00.

680

0.68

01.

360

-109

3.1

-534

4.2

14.8

-103

7.3

-577

.9-4

.458

91.

50.

140

0.14

01.

220

0.68

00.

680

1.36

030

7.0

32.7

787.

8-2

560.

7-6

252.

672

6.9

Att

hiss

tage

each

laye

rmay

bede

signe

dby

appl

ying

the

follo

win

geq

uatio

ns(

=45

°):

ccd

tf

tv

sin

Sd cos

2sa

fety

verif

icat

ion

onco

ncre

tesid

e

n Rdx

=n S

dx+

v Sd

cot

requ

ired

resis

tanc

eal

ong

xdi

rect

ion

nn

Rdy

Sdy

Sdv cot

requ

ired

resi

stanc

eal

ong

ydi

rect

ion

from

whi

ch,i

fres

ults

atis

fied,

the

rein

forc

emen

tare

asm

aybe

calc

ulat

edas

:

Asx

n fRdx

yd

;A

sy

n fRdy

yd

Ifco

ncre

test

reng

thre

quire

men

tis

not

satis

fied,

anin

crea

sela

yer

thic

knes

ssh

allb

epr

ovid

edun

tilve

rific

atio

nis

met

;in

this

case

new

valu

esfo

rth

ela

yer

actio

nha

ving

chan

ged

zval

ue.

Itca

nbe

notic

eth

atif

n Rdx

orn R

dyva

lue

are

nega

tive,

aco

mpr

essio

nfo

rce

ispr

esen

tal

ong

that

dire

ctio

nan

dno

rein

forc

emen

tis

requ

ired;

ifbo

thth

en R

dxan

dn R

dyar

ene

gativ

eit

ispo

ssib

leto

omit

the

rein

forc

emen

tin

both

the

dire

ctio

nsbu

t,in

this

case

the

verif

icat

ion

ispe

rform

edal

ong

the

prin

cipa

lco

mpr

essio

ndi

rect

ion

inth

eco

ncre

tesu

bjec

ted

tobi

axia

lcom

pres

sion

and

the

chec

king

equa

tion

is:

cSd

xSd

ySd

xSd

yt

nn

nn

vt

24

2

Sd2cd

1f

Fort

heco

nsid

ered

elem

ents,

one

obta

ins:

Tabl

e6.

14

Page 45: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-61

Tabl

eof

Cont

ent

Top

Laye

rDes

ign

Bot

tom

Laye

rDes

ign

Elem

.c

f cd1

/2A

syA

sxc

f cd1

/2A

syA

sx

[MPa

][k

N/m

][c

m2 /m

][c

m2 /m

][M

Pa]

[kN

/m]

[cm

2 /m]

[cm

2 /m]

648

-35.

0-1

7.1

0.0

0.0

-30.

0-1

7.1

0.0

0.0

93-2

4.9

-17.

10.

00.

0-2

2.4

-17.

10.

00.

032

0-3

8.2

-17.

10.

00.

0-7

.4-1

7.1

0.0

0.0

589

-11.

3-1

2.0

25.2

18.9

-45.

6-1

7.1

0.0

0.0

Itca

nbe

notic

eth

atve

rific

atio

nfo

rcon

cret

ein

com

pres

sion

isno

tsat

isfie

dfo

rany

laye

rsex

cept

for

elem

ent

589

top

laye

ran

del

emen

t320

botto

mla

yer.

Thus

,an

incr

easin

gof

laye

rthi

ckne

ssis

requ

ired

and

new

valu

esof

plat

eac

tions

are

obta

ined

:Ta

ble

6.15

Elem

.h

t st i

t cy s

y iz

nSd

y,s

nSd

x,s

v Sd,

sn

Sdy,

in

Sdx,

iv S

d,i

[m]

[m]

[m]

[m]

[m]

[m]

[m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

/m]

[kN

/m]

648

1.5

0.30

00.

240

0.96

00.

600

0.63

01.

230

-716

.6-5

040.

814

.1-1

062.

0-4

054.

7-8

.893

0.96

30.

220

0.19

00.

553

0.37

20.

387

0.75

8-3

588.

5-1

465.

566

.5-2

157.

8-3

144.

8-1

29.4

320

1.5

0.34

00.

140

1.02

00.

580

0.68

01.

260

-117

9.8

-576

8.3

16.0

-950

.6-1

53.8

-5.5

589

1.5

0.14

00.

430

0.93

00.

680

0.53

51.

215

708.

787

0.1

794.

7-2

962.

5-7

090.

072

0.0

whi

chle

adto

the

follo

win

gva

lues

:Ta

ble

6.16

Top

Laye

rDes

ign

Bot

tom

Laye

rDes

ign

Elem

.c

f cd1

/2A

syA

sxc

f cd1

/2A

syA

sx

[MPa

][k

N/m

][c

m2 /m

][c

m2 /m

][M

Pa]

[kN

/m]

[cm

2 /m]

[cm

2 /m]

648

-16.

8-1

7.1

0.0

0.0

-16.

9-1

7.1

0.0

0.0

93-1

6.3

-17.

10.

00.

0-1

6.6

-17.

10.

00.

032

0-1

7.0

-17.

10.

00.

0-6

.8-1

7.1

0.0

0.0

589

-11.

4-1

2.0

34.6

38.3

-16.

8-1

7.1

0.0

0.0

Ofc

ours

e,m

inim

ava

lues

shou

ldbe

adop

ted

forA

sxan

dA

syif

nore

info

rcem

enta

reas

are

requ

ired.

For

elem

ent5

89,t

heA

sxan

dA

syva

lue

are

requ

ired

atth

ece

ntro

idof

the

laye

r,w

here

asth

eyar

ear

rang

edat

0.07

mfr

omth

eex

tern

alsu

rfac

eof

the

slab

inan

ecce

ntric

posit

ion

with

resp

ect

tom

iddl

epl

ane

ofth

ela

yer;

so,

the

amou

ntof

rein

forc

emen

tpro

vide

dha

sto

bech

ange

dto

resto

reeq

uilib

rium

cond

ition

s.Th

isva

riatio

nm

aybe

asse

ssed

with

the

aid

ofth

em

echa

nism

pict

ured

inFi

g.6.

51:

EC2�

wor

ked

exam

ples

6-62

Tabl

eof

Cont

ent

Fig

.6.5

1Sh

elle

lem

ente

quili

briu

min

one

dire

ctio

nwi

thtw

ore

info

rcem

entl

ayer

sonl

y

The

new

forc

esac

ting

onth

ere

info

rcem

ents

beco

me:

nn

ht

bn

tb

zs

Sds

si

Sdi

ii

,,

22

n i=

n Sd,

s+

n Sd,

in s

Fort

hein

vesti

gate

del

emen

ts,t

hefo

llow

ing

area

shav

ebe

ende

tect

ed.

Tabl

e6.

17

Forc

esre

ferr

edto

tens

ion

steel

leve

lTo

pla

yerr

einf

Botto

mla

yerr

einf

Elem

.n

s,y

ni,y

ns,

xn

i,xA

syA

sxA

syA

sx

[kN

/m]

[kN

/m]

[kN

/m]

[kN

/m]

[cm

2 /m]

[cm

2 /m]

[cm

2 /m]

[cm

2 /m]

648

-702

.5-1

070.

8-5

026.

6-4

063.

60.

00.

00.

00.

093

-352

2.0

-228

7.2

-139

9.0

-327

4.3

0.0

0.0

0.0

0.0

320

-116

3.8

-956

.1-5

752.

3-1

59.3

0.0

0.0

0.0

0.0

589

1503

.5-2

242.

516

64.8

-637

0.0

34.6

38.3

0.0

0.0

The

prev

ious

proc

edur

esh

ould

bere

peat

edfo

rall

the

elem

ents

ofth

estr

uctu

ralm

odel

findi

ngth

eam

ount

ofre

info

rcem

ent

topr

ovid

ein

the

slab;

itis

usef

ul,

toco

ntro

lth

estr

uctu

ralb

ehav

iour

and

fora

best

fitte

dre

info

rcem

entl

ayou

t,to

sum

mar

iseth

ere

sults

ina

visu

alm

ap.

Veri

ficat

ion

toBu

rstin

gFo

rce

For

the

calc

ulat

ion

ofth

ebu

rstin

gfo

rce

the

sym

met

ricpr

isman

alog

yis

used

,eva

luat

ing

the

heig

htof

the

prism

soth

athi

sce

ntro

idre

sults

coin

cide

ntw

ithth

ece

ntro

idof

pres

tress

ing

tend

ons.

For

the

sake

ofsi

mpl

icity

,on

lyth

elo

ngitu

dina

ldi

rect

ion

ofpr

estre

ssin

gte

ndon

isco

nsid

ered

with

resp

ectt

oth

eve

rtica

lpla

ne,b

uttra

nsve

rse

forc

edu

eto

burs

ting

effe

ctsh

ould

beal

soca

lcul

ated

inth

eho

rizon

tal

plan

ean

dfo

rtra

nsve

rse

pres

tress

ing

too.

Page 46: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-63

Tabl

eof

Cont

ent

Fig

.6.5

2G

eom

etric

dim

ensio

nfo

rbur

stin

gca

lcul

atio

n

Chec

king

situ

atio

nis

repr

esen

ted

inFi

g.6.

52,

and

the

mos

tun

favo

urab

lesit

uatio

noc

curs

whe

na

singl

ete

ndon

iste

nsio

ned;

cons

ider

ing

the

low

erle

vel

ofte

ndon

(firs

tte

nsio

ned)

the

heig

htof

the

prism

resu

lts:

h bs

=2

0.6

=1.

2m

and

hisl

engt

h,fo

rend

anch

ored

tend

on,i

s:l bs

=h b

s=

1.2

mw

hile

the

wid

thfo

llow

sfr

omth

epo

ssib

leen

larg

emen

tof

the

anch

orpl

ate

that

may

beas

sum

edeq

ualt

o0.

43m

,cor

resp

ondi

ngto

the

trans

vers

esp

acin

gof

long

itudi

nall

ower

tend

ons.

The

desig

nfo

rce

pert

endo

nha

sbee

nev

alua

ted

bym

eans

ofth

efo

llow

ing

expr

essio

n:

Ff .

ASd

ptk

sp11

518

0011

513

919

103

.41

34kN

The

burs

ting

forc

efo

llow

sfro

mth

em

omen

tequ

ilibr

ium

alon

gse

ctio

nA

-A:

Nz

Fbs

bsSd

05

12

21

11

.(

)n

nt

nt

=85

2.6

kN

whe

re:

t 1=

0.07

5m

dista

nce

betw

een

the

cent

roid

ofte

ndon

sabo

vese

ctio

nA

-Ato

the

cent

roid

ofth

epr

ism

;

t 2=

0.30

0m

dista

nce

betw

een

the

cent

roid

ofco

ncre

test

ress

bloc

kab

ove

sect

ion

A-A

toth

ece

ntro

idof

the

prism

;

EC2�

wor

ked

exam

ples

6-64

Tabl

eof

Cont

ent

n 1,n

2nu

mbe

rsof

tend

ons

abov

ean

dbe

low

sect

ion

A-A

,re

spec

tivel

y:co

nsid

erin

gth

ean

chor

plat

eas

rigid

ava

lue

of0.

5m

aybe

assu

med

;

1=1

.1su

pple

men

tary

parti

alsa

fety

fact

orag

ains

tove

rstre

ssin

gby

over

pum

ping

.Bu

rstin

gfo

rce

shal

lbe

resis

ted

byan

area

ofre

info

rcem

ents

teel

of:

As,b

s=

Nbs

/fyd

=19

.61

cm2

distr

ibut

edw

ithin

l bs/3

tol bs

,(i.e

.fro

m0.

40m

to1.

20m

)fro

mth

ean

chor

plat

e.Th

usth

eef

fect

ive

area

ona

met

erle

ngth

,may

befo

und

byth

efo

llow

ing:

A ss

A bs

bss

bs,

,.

.43

..4

2 3

1961

012

00

l bs

57.0

cm2 /m

2

that

may

bepr

ovid

edw

ithtie

sha

ving

diam

eter

of22

mm

and

spac

ing

both

trans

vers

ally

and

long

itudi

nally

of25

0m

m(s

eeFi

g.53

);in

fact

22/2

525

corr

espo

nds

to60

.82

cm2 /m

2.

Fig

.53

Burs

ting

rein

forc

emen

tarr

ange

men

t

Veri

ficat

ion

tosp

allin

gfo

rce

The

spal

ling

forc

em

aybe

calc

ulat

edw

ithth

eeq

uiva

lent

pris

man

alog

y.A

sfo

rbu

rstin

gve

rific

atio

n,on

lyth

elo

ngitu

dina

ldi

rect

ion

isco

nsid

ered

;fu

rther

mor

e,sp

allin

gef

fect

sar

iseif

uppe

rten

don

are

tens

ione

dfir

stly

(the

ecce

ntric

ityle

adst

ote

nsio

nst

ress

es).

Thus

,a

sect

ion

with

abr

eadt

hof

0.43

man

da

heig

htof

1.50

mha

sto

beve

rifie

dfo

rone

tend

onte

nsio

ning

.Th

ele

ngth

ofth

epr

ismfo

rend

anch

ored

tend

on,i

seq

ualt

oth

eov

eral

lhei

ghto

fth

ese

ctio

n,i.e

.l sl

=1.

50m

.C

onsid

erin

gan

ecce

ntric

ityfo

rup

per

pres

tress

ing

tend

onof

0.35

m,t

heex

trem

estr

esse

satt

heen

dof

pris

mle

ngth

are

calc

ulat

edby

mea

nsof

the

beam

theo

ry;f

ora

pres

tress

ing

forc

eF S

d=

4134

.0kN

they

resu

lt(n

egat

ive

ifco

mpr

essiv

e):

top

bott

MPa

MPa

om.4

3.

..4

3.

. .F Sd

10

150

035

60

150

1538

256

2

The

sect

ion

alon

gw

hich

nosh

earf

orce

resu

lts,i

spla

ced

at0.

428

mfro

msl

abbo

ttom

fibre

(see

Fig

54)a

ndth

em

omen

tfor

equi

libriu

mtu

rnso

ut:

Page 47: Beam Model Calculation

EC2�

wor

ked

exam

ples

6-65

Tabl

eof

Cont

ent

Msl

bott

2 30

214

010

23

om.

.43

33.6

1kN

m

Fig

.54

Cal

cula

tion

sche

me

fors

palli

ng

Ass

umin

gz s

l=0.

5l sl

and

b sl=

0.43

m,t

hem

axim

umsp

allin

gfo

rce

turn

sout

:N

sl=

Msl

/zsl

=44

.81

kND

isreg

ardi

ngan

yco

ncre

tete

nsile

resis

tanc

e,th

eam

ount

ofre

info

rcem

enti

s:

As=

Nsl

/fyd

=1.

031

cm2

plac

edpa

ralle

lto

the

end

face

inits

clos

evi

cini

ty.

EC2�

wor

ked

exam

ples

6-66

Tabl

eof

Cont

ent

Page 48: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-1

Tabl

eof

cont

ent

SEC

TIO

N7.

SER

VIC

EA

BIL

ITY

LIM

ITST

AT

ES

–W

OR

KE

DE

XA

MPL

ES

EX

AM

PL

E7.

1E

valu

atio

nof

serv

ice

stre

sses

[EC

2cl

ause

7.2]

Eva

luat

eth

eno

rmal

com

pres

sive

forc

ean

dof

the

asso

ciat

edbe

ndin

gm

omen

tin

the

sect

ion

ofFi

gure

7.1,

with

the

boun

dary

cond

ition

s

a)c c

2ck

(yh)

0;(y

0)k

f;

b)c

1ck

s3

sk

(y0)

kf

(yd)

kf

Then

,eva

luat

eth

em

ater

ials

stra

insf

rom

the

stre

sses

c)

N0

=-8

00kN

;M0

=40

0kN

m.

Fina

lly,c

alcu

late

the

coup

lesM

,Nas

soci

ated

toth

eth

ree

path

sd)

M/N

=-0

.5m

;e)N

=N

0=

-800

kN;f

)M=

M0

=40

0kN

m,t

hat,

linea

rlych

angi

ngM

N,o

rM

,N,r

espe

ctiv

elyw

ithco

nsta

ntno

rmal

forc

eor

cons

tant

bend

ing,

keep

the

sect

ion

toth

eul

timat

ete

nsio

nst

ate

unde

rloa

d.

Fig.

7.1.

Rect

angu

lars

ection

,cal

cula

tion

ofser

vices

tresse

s.

The

follo

win

gda

taar

egi

ven:

f ck=

30M

Pa,f

yk=

450

MPa

,e

=15

.

Cons

ider

ing

Fig.

7.1,

we

have

d=

550

mm

;d�=

50m

m;h

=60

0m

mA

s=6

314=

1884

mm

2 ;=

1

The

boun

dary

cond

ition

sfr

omth

efir

stex

ercis

ese

tth

ene

utra

laxi

son

the

bord

erof

the

botto

mse

ctio

n,th

atis

y n=

h.Fo

rthi

svalu

eit

resu

lts3

22

2

2

600

400

400

600

300

1518

8450

550

12e

300

600

400

1518

84(

600)

2

and

then

e=

-120

.65

mm

,*

63

ynS88

.96

10m

m.

The

seco

ndco

nditi

onin

the

first

exer

cise,

assu

min

gk 2

=0.

45,c

anbe

writ

ten

as

6

N(

600)

0.45

3088

.96

10

EC2�

wor

ked

exam

ples

7-2

Tabl

eof

Cont

ent

and

then

N=

-200

1.16

kN,

M=

Ne=

-200

1.16

(-120

.65)

10-3

=24

1.49

kNm

.Th

ete

nsio

nst

ress

post

ulat

edby

the

seco

ndex

erci

segi

ves

the

follo

win

gex

pres

sion

for

the

neut

rala

xis

n3

yk

e2

ck

d55

0y

235.

71m

mk

f0.

845

01

115

0.6

30k

f

and

the

com

pres

sed

stee

lten

sion

and

the

stre

ssco

mpo

nent

sare

'n

ss

ss

n

d'y

5023

5.7

0.59

dy

550

235.

7

N=

-0.6

3040

023

5.7/

2+0.

845

018

84(1

-0.5

9)10

-3=

-570

.48

kN

M=

(-0.6

3040

023

5.7/

2(2

35.7

/3-3

00)+

0.8

450

1884

(1-0

.59)

250)

10-6

=45

7.5

kNm

e=

-457

.5·1

06 /570

.48·

103

=-8

01.9

5m

mCo

nsid

erin

gth

eth

irdex

erci

se

340

0e

1050

0mm

800

and

22

3 nn

n

n2 n

n

400

y15

1884

550

y50

y3

y20

040

0y

1518

8460

02

y2

this

equa

tion

isite

rativ

elyso

lved

:

y n=

272.

3m

m,

*3

3ynS

1326

310

mm

and

then

the

tens

iona

lsta

teis

3

c6

800

10(

272.

3)16

.42M

Pa13

.263

10

s16

.42

(550

272.

3)15

251.

18M

Pa27

2.3

' s16

.42

(50

272.

3)15

201.

07M

Pa27

2.3

Beca

use

the

cond

ition

e=

-500

mm

impl

iest

hatt

hene

utra

laxi

spos

ition

islo

wer

than

the

one

prev

ious

lyev

aluat

edas

sum

ing

the

max

imal

stre

sses

for

both

mat

erial

s,th

eul

timat

ete

nsio

nst

ate

corr

espo

nds

toth

em

axim

alte

nsio

nad

mitt

edfo

rcon

cret

e.If

we

cons

ider

toch

ange

M,

Nke

epin

gco

nsta

ntth

eec

cent

ricity

,the

tens

iona

lsta

tech

ange

prop

ortio

nally

and

we

can

stat

e

ck

00

c

0.6f

NM

1.09

6N

M.

Onc

eth

eco

ncre

teul

timat

eco

mpr

essiv

elim

itsta

teis

reac

hed,

the

stre

ssis

N=

1.09

6N0=

-876

.80

kN;M

=1.

096

M0

=43

8.4

kNm

.

Page 49: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-3

Tabl

eof

Cont

ent

Wor

king

with

cons

tant

norm

alfo

rce

(N=

N0)

the

ultim

ate

limit

stat

efo

rthe

conc

rete

tens

ion

lead

sto

0n

ck* yn

N(

y)

0.6f

S

and

then

n3

2 nn

y0.

630

400

800

10y

1518

8460

02

y2

Solv

ing

with

resp

ectt

oy n

2 nn

2n ' s sy

60y

8479

50

y30

.25

30.2

584

795

262.

51m

m(5

026

2.51

)0.

630

1521

8.57

MPa

262.

51(5

5026

2.51

)0.

630

1529

5.69

MPa

262.

51an

dth

en

640

026

2.51

262.

51M

0.6

3030

018

84(2

95.6

921

8.57

)25

010

442.

56kN

m2

36

3

442.

5610

e=-

553.

2mm

800

10K

eepi

ngco

nsta

ntth

ebe

ndin

gm

omen

t(M

=M

0),th

elim

itst

ate

cond

ition

for

the

conc

rete

stre

ssis n

ck* yn

N(

y)

0.6f

San

dth

en0

0n

*ck

yn

MM

(y)

eN

0.6f

S

and * yn

0n

n*

*yn

ckyn

IM

(y)

hy

S0.

6f

S2

As

66

30

ck

M40

010

22.2

210

mm

0.6

f0.

630

the

prev

ious

num

eric

form

beco

mes

22

36

nn

nn

n2 n

n

400

y15

1884

550

y50

y22

.22

10y

3y

300

400

y15

1884

600

2y

2an

dite

rativ

ely

solv

ing

EC2�

wor

ked

exam

ples

7-4

Tabl

eof

Cont

ent

n ' s sy39

5mm

(50

395)

0.6

3015

235.

82M

Pa39

5(5

5039

5)0.

630

1510

5.95

MPa

395

6

400

395

N0.

630

1884

(105

.95

235.

82)

1666

.67k

N2

400

395

395

M0.

630

300

1884

(105

.95

235.

82)

250

1040

0.34

kNm

23

e=-2

40m

m

Figu

re7.

2re

ports

the

resu

ltsob

tain

edin

the

evalu

atio

nin

term

soff

orce

sand

stres

ses.

Fig.

7.2.

Resu

ltsfor

diffe

rentl

imit

distr

ibut

ionso

fstre

sses.

Asa

rem

ark,

just

inth

eca

sec)

the

conc

rete

tens

ion

limit

stat

eun

derl

oad

isno

trea

ched

whi

lein

the

case

a)(k

1=0.

45)a

ndth

eot

herc

ases

b)d)

e)f)

(k1=

0.65

)res

pect

ivel

yre

ach

the

tens

ion

ultim

ate

stat

esun

der

load

asso

ciat

edto

non

linea

rvi

scos

ityph

enom

ena

and

min

imal

tens

ion

inth

epr

esen

ceof

parti

cular

com

bina

tions

.O

nth

eot

her

hand

,th

ete

nsio

nul

timat

est

ate

unde

rloa

dfo

rtie

dst

eeli

sgot

just

inth

eca

seb)

.2B

Page 50: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-5

Tabl

eof

Cont

ent

EX

AM

PL

E7.

2D

esig

nof

min

imum

rein

forc

emen

t[E

C2

clau

se7.

3.2]

Let�s

cons

ider

the

sect

ion

inFi

gure

7.3

with

the

follo

win

gge

omet

ry:

A=

1.92

5á10

6m

m2

;yG

=80

9m

m;I

=71

.82á

1010

mm

4 ;

Wi=

7.25á1

08m

m3 ;r

2=

I/A

=39

.35á

104

mm

2

Fig.

7.3.

Box

-sect

ion,d

esign

ofm

inim

umrei

nfor

cemen

t.

Eva

luat

eth

em

inim

umre

info

rcem

enti

nto

the

botto

msla

bin

the

follo

win

gca

ses:

App

licat

ion

ofth

efir

stcr

acki

ngm

omen

tMcr

App

licat

ion

ofan

axial

com

pres

sive

forc

eN

=-6

000

kN,a

pplie

din

the

poin

tPat

250

mm

from

the

botto

mbo

rder

ofth

eco

rres

pond

ing

crac

king

mom

ent.

Cons

ider

the

follo

win

gda

ta:

f ck=

45M

Pa;

f ct,ef

f=

3.8

MPa

;s=

200

MPa

;k

=0.

65(h

w>

1m)

The

give

nsta

tem

ents

impl

y:

s25

0/

1800

0.13

88

f30

0/

1800

0.16

67

sf

10.

6945

0 s,m

in0.

653.

8/20

00.

0123

5

Case

a)

The

appl

icat

ion

ofcr

acki

ngm

omen

tisa

ssoc

iate

dto

the

neut

rala

xisp

ositi

ony n

=y G

,and

then

809/

1800

0.44

94.

Itre

sults

also

sf

10.

4860

2an

dfo

rthe

web

s,m

in3

0.69

452(

10.

1667

0.44

94)

0.01

235

0.4

11

0.16

670.

4494

0.00

208

41

0.44

94

EC2�

wor

ked

exam

ples

7-6

Tabl

eof

Cont

ent

2s,

min

A0.

0020

830

018

0011

23m

m

this

rein

forc

emen

thas

tobe

puti

nth

ew

ebtie

dar

eaw

ithhe

ight

over

the

botto

msla

ba

=18

00�

809�

300

=69

1m

m.

We

use

(5+

5)12

mm

equi

vale

ntto

1130

mm

2 .

Refe

rrin

gto

the

botto

msla

bw

ege

t

f9

10.

812

8an

dit

follo

ws:

s,m

in2(

10.

4494

)0.

1667

0.01

235

0,45

0.00

943

10.

4494

2s,

min

A0.

0094

330

015

0042

43m

m

We

use

(14+

14)

14m

meq

uiva

lent

to43

12m

m2 .

The

rein

forc

emen

tsch

eme

isre

port

inFi

gure

7.4

Fig.

7.4.

Min

imum

reinf

orcem

ent,

case

(a).

Case

b)

The

crac

king

mom

enta

ssoc

iated

toth

eax

ialfo

rce

N=

-600

0kN

,with

ecce

ntric

itye N

=18

00-

809-

250

=74

1m

mde

rives

from

the

relat

ion

crN

ct,e

ffi

i

NA

M1

ef

WA

W

and

then

:3

68

6cr

68

6000

1074

11.

825

10M

13.

87.

2510

1095

85kN

m1.

825

107.

2510

the

ecce

ntric

ityof

the

norm

alfo

rce

inth

epr

esen

ceof

Mcr

isth

en:

3e

9585

1060

0074

185

6mm

and

the

neut

rala

xisp

ositi

onre

sults

from

the

rela

tion

Page 51: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-7

Tabl

eof

Cont

ent

24

nG

r39

.35

10y

y80

912

69m

me

856

,=

0.70

50

Cons

ider

ing

the

web

,with

*h1.

8h

we

dedu

ce:

s,m

in0.

6945

2(1

0.16

670.

7050

)0.

0123

50.

41

10.

1667

0.70

500.

0004

63

1.8(

10.

7050

)

2s,

min

A0.

0004

630

018

0024

8mm

We

use

410

equi

valen

tto

314

mm

2 .

The

bars

have

tobe

loca

ted

inth

etie

dpa

rtof

the

web

fora

nex

tens

ion

a=

1800

-126

9-30

0=

231

mm

over

the

botto

msla

b

Inth

ebo

ttom

slab

we

have

:

f9

10.

812

8an

dit

resu

lts

s,m

in2(

10.

705)

0.16

670.

0123

50,

450.

0079

71

0.70

52

s,m

inA

0.00

797

300

1500

3586

mm

We

use

(12+

12)

14m

meq

uiva

lent

to36

92m

m2 .

The

rein

forc

emen

tsch

eme

isre

porte

din

Figu

re7.

5

Fig.

7.5.

Min

imum

reinf

orcem

ent,

case

(b).

3B

EC2�

wor

ked

exam

ples

7-8

Tabl

eof

Cont

ent

EX

AM

PL

E7.

3E

valu

atio

nof

crac

kam

plitu

de[E

C2

clau

se7.

3.4]

The

crac

kw

idth

can

bew

ritte

nas

:

s,cr

sk

31

24

ss

s

w1

kc

kk

kE

(7.1

)

with

ss,

crt

ct,e

ffe

s

kf

1(7

.2a)

11

min

2.5

1;

;3

2(7

.3)

Ass

umin

gth

epr

escr

ibed

valu

esk 3

=3.

4,k 4

=0.

425

and

cons

ider

ing

the

bend

ing

case

(k2=

0.5)

with

impr

oved

boun

dre

info

rcem

ent(

k 1=

0.8)

,the

(7.2

)we

get

s,cr

sk

ss

s

w1

3.4

c0.

17E

(7.4

)

The

(7.4

)can

beim

med

iately

used

asve

rifica

tion

form

ula.

Asa

nex

ampl

ele

t�sco

nsid

erth

ese

ctio

nin

Figu

re7.

6

Fig.

7.6.

Rein

forced

conc

retes

ection

,cra

cksa

mplit

udee

valu

ation

assu

min

ge

=15

,d=

548m

m,

d�=

46.0

mm

,c=

40m

m,

b=40

0mm

,h=

600m

m,

M=

300k

Nm

,A

s=27

12m

m2

(624

),A

s�=45

2mm

2(4

12),

f ck=

30M

Pa,f

ct,ef

f=f ct

m=

2.9M

Pa

Refe

rrin

gto

ash

ortt

ime

actio

n(k

t=0.

6).

Itre

sults

then

=45

2/27

12=

0.16

7,=

548/

600=

0.91

3,�=

460/

600=

0.07

67,

s=27

12/(

400

600)

=0.

0113

And

the

equa

tion

fort

hene

utra

laxi

syn

is

2 nn

n40

0y

1527

1254

8y

0.16

746

y0

2an

dth

en

Page 52: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-9

Tabl

eof

Cont

ent

2 nn

2n

ny23

7.4y

1130

260

y23

7.8

y11

8.7

118.

711

3026

237.

8mm

,0.

3963

h60

0Th

ese

cond

orde

rmom

entr

esul

ts

n

22

*3

94

y40

0I

237.

815

2712

548

237.

80.

167

4623

7.8

5.96

10m

m3

and

we

dedu

ce6

9s

1530

010

548

237.

8/5

.96

1023

4MPa

the

valu

eto

bead

opte

dis

the

low

est

betw

een

2.5(

1-0.

913)

=0.

2175

;(1-

0.39

63)/

3=0.

2012

;0.

5.Th

en=

0.20

12.

The

adop

ted

stat

emen

tsle

adto

s,cr k

5

0.20

120.

0113

0.6

2.9

115

57.0

8MPa

0.01

130.

2012

234

57.0

824

w1

3.4

400.

170.

2012

0.18

4mm

210

234

0.01

13

4B

EC2�

wor

ked

exam

ples

7-10

Tabl

eof

Cont

ent

EX

AM

PL

E7.

4.D

esig

nfo

rmul

asde

riva

tion

fort

hecr

acki

nglim

itst

ate

[EC

2cl

ause

7.4]

8B7.4.

1E

xact

met

hod

Itis

inte

rest

ing

tode

velo

pth

e(7

.4)t

ous

eit

asa

desig

nfo

rmul

a.In

parti

cular

,sta

ted

b,h,

d,d�

,b,a

ndfix

edM

,we

wan

tto

dedu

ceth

em

etal

rein

forc

emen

tam

ount

As

and

itsde

sign

tens

ion

sin

orde

rto

have

acr

ack

ampl

itude

wk

low

erth

anth

efix

edva

lue

kw

.Th

ead

imen

siona

lcalc

ulus

lead

sto

2e

se

s1

1'

02

(7.5

)

ect

mt

s2

23

s

fk

23n

'(7

.6)

setti

ng

20 cr

tct

m

MM b

hM

kf

6(7

.7)

Ded

ucin

gsfr

om(7

.5)a

ndw

ithits

subs

titut

ion

inth

e(7

.6)w

ege

t2

se

21

'(7

.8)

32

e2

2

2p

3p

'1

'(7

.9)

with

p=s/

(ktf c

tm)

(7.1

0)

From

(7.4

),w

here

kw

w,a

fters

ome

calc

ulat

ions

we

dedu

ce0 k

s

s

wp

n3.

4c

0.17

(7.1

1)

setti

ngs

k0k

tct

m

Ew

wk

f(7

.12)

Com

bini

ng(7

.8)a

nd(7

.11)

,the

(7.9

)is

02

ee

ke

22

22

e

23

22

2w

'1

3.4c

0.34

'1

'

32

'1

'

Page 53: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-11

Tabl

eof

Cont

ent

(7.1

3)th

e(7

.13)

,num

eric

ally

solv

ed,a

llow

sth

ede

term

inat

ion

ofth

ene

utra

laxi

spo

sitio

nan

dth

en,

usin

gth

e(7

.11)

(7.8

),th

eev

alua

tion

ofth

ere

info

rcem

entt

ensio

nan

dits

amou

nt..

Ifit

isno

tth

eca

se,i

tis

nece

ssar

yto

set

inth

e(7

.13)

=2.

5(1-

)an

dth

enre

-eva

luat

ing

,bei

ngth

eva

lue

=0.

5pr

actic

ally

impo

ssib

lefo

rben

ding

prob

lem

s.Th

epr

oced

ure,

aimed

toth

ede

term

inat

ion

ofth

ere

info

rcem

ent

amou

ntan

dits

tens

ion

corr

espo

ndin

gto

fixed

crac

kam

plitu

deva

lues

and

stre

ssle

vel,

requ

irest

ose

tbef

ore

the

valu

eof

the

bars

diam

eter

.

Alte

rnat

ively

,it

ispo

ssib

leto

set

the

tens

iona

llev

els,

for

exam

ple

coin

cide

ntw

ithth

epe

rmiss

ible

one,

and

toev

aluat

eth

eco

rres

pond

ing

rein

forc

emen

tam

ount

san

dth

em

axim

alba

rsdi

amet

er.I

nth

isca

se,a

sth

epa

ram

eter

pis

defin

ed,t

hene

utra

laxi

sis

obta

ined

from

(7.9

),s

from

(7.7

)an

dth

em

axim

aldi

amet

erde

rives

from

(7.1

1)so

lved

with

resp

ect

to,

whi

chas

sum

esth

efo

rm:

ss

okm

axe

s

5.88

w2c

(p)

(7.1

4)

5B7.4.

2A

ppro

xim

ated

met

hod

The

appl

icat

ion

ofth

epr

oced

ure

disc

usse

dab

ove

isqu

itelab

orio

usas

itre

quire

sto

itera

tivel

yso

lve

the

(7.1

3).A

nal

tern

ativ

epr

oced

ure,

easie

rto

beap

plied

,con

sisti

nth

est

atem

entt

hat

the

leve

rar

mh 0

isco

nsta

ntan

din

depe

nden

tfro

man

deq

uiva

lentt

o0.

9d.I

nth

isw

ay,

we

have

sAs0

.9d=

Man

dth

en

s=0.

185

/(p

)(7

.15)

the

(7.4

)writ

ten

for

kw

wim

med

iatel

ygi

ves

se

sk

ss

s

w1

13.

4c0.

17E

p(7

.16)

aimin

gto

afu

rther

simpl

ifica

tion

ofth

epr

oble

m,l

et�s

state

=0.

9,=

0.24

3an

das

sum

ing

byde

finiti

on

*1.

181

10.

185

1c

u0k

2w

u(7

.17)

the

(7.1

6)af

ters

ome

algeb

raha

sthe

form

2e

1e

12

p5

*3.

4u0.

20p

*17

u5u

0*

(7.1

8)

the

(11.

67)i

sea

syto

solv

e,an

dto

geth

erw

ithth

e(7

.15)

and

(7.1

1),l

eads

toth

ede

sred

valu

esse

s.

Inth

isca

seto

o,,i

fwe

sett

heva

lue

ofs,

the

solu

tion

for(

7.18

)with

resp

ectt

olea

dsto

the

relat

ion

EC2�

wor

ked

exam

ples

7-12

Tabl

eof

Cont

ent

**

eok

max

*2

e

17c(

p)

5w

pp

(7.1

9)

that

defin

esth

em

axim

alba

rsdi

amet

er,w

hich

,,as

soci

ated

toth

ere

info

rcem

enta

mou

ntgi

ven

byth

e(7

.15)

,allo

wst

osa

tisfy

the

crac

king

ultim

ate

stat

eco

rres

pond

ing

toa

fixed

valu

eof

the

stee

lten

sion.

6B

Page 54: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-13

Tabl

eof

Cont

ent

EX

AM

PL

E7.

5A

pplic

atio

nof

the

appr

oxim

ated

met

hod

[EC

2cl

ause

7.4]

Let�s

use

the

desc

ribed

proc

edur

eto

the

sect

ion

inFi

gure

7.7.

Fig.

7.7.

Rein

forced

conc

reteS

ection

,rein

forcem

entd

esign

forth

ecra

ckin

gulti

mate

state.

Ass

umin

gb=

1000

mm

;h=

500m

m;c

=50

mm

;=

26m

m;f

ck=

33M

Pa;M

=60

0kN

m,d

esig

nth

ese

ctio

nto

have

acr

ack

ampl

itude

kw

0.30

mm

,k

kw

0.20

mm

,w

0.10

mm

.

Itre

sults

f ctm=

0.3. 33

2/3 =

3.08

6MPa

=(5

00-6

3)/5

00=

0.87

4M

0 cr=

0.6. 3.

086. (1

000. 50

02 /6). 10

-6=

77.1

5kN

m(s

eeex

.7.1

)

=60

0/77

.15=

7.77

*=7.

77/(

1-1.

18/7

.77)

=9.

16u 1

=50

/26=

1.92

Def

ined

max

kw

0.30

mm

the

max

imal

ampl

itude

,in

the

thre

eca

ses

unde

rexa

min

atio

nw

eca

nse

tm

axk

kw

ww

kw

here

k w=

1;2/

3;1/

3.Th

enin

age

nera

lfor

m5

0kw

w0.

32

10w

k32

404

k0.

63.

086

2w

w32

404

uk

1246

k26

2w

7.77

0.20

15p

59.

163.

41.

92p

9.16

1715

1.92

512

46k

09.

167.

77

and

then

2w

p23

5.93

p44

8557

067

k0

and

then

ww

pk

117.

965

1840

0.74

5706

7k

Usin

gth

epr

evio

usre

latio

n,to

geth

erw

ithth

e(7

.15)

and

(7.1

0),

inth

eth

ree

case

she

reco

nsid

ered

k w=

1,k

w0.

3m

m,

p(1)

=15

6.75

s0.

185

7.77

10.

0104

915

6.75

0.87

4,

As(1

)=0.

0104

9á50

0á10

00=

5245

mm

2

s(1

)=0.

6á3

.086á1

56.7

5=

290

MPa

k w=

2/3,

kw

0.2

mm

,p

(2/3

)=11

9.62

s0.

185

7.77

23

0.01

375

119.

620.

874

,A

s(2

/3)=

0.01

375á

500á

1000

=68

75m

m2

EC2�

wor

ked

exam

ples

7-14

Tabl

eof

Cont

ent

s(2

/3)=

0.6á

3.08

6á11

9.62

=22

1M

pa

k w=

1/3,

kw

0.1m

m,

p(1

/3)=

75.4

8

s0.

185

7.77

13

0.02

179

75.4

80.

874

,A

s(1

/3)=

0.02

179á

500á

1000

=10

895

mm

2

s(1

/3)=

0.6á3

.086á7

5.48

140

MPa

The

thre

ese

ctio

nsar

ere

porte

din

Figu

re7.

7;th

em

etal

area

sar

eov

eres

timat

ed,a

nd26

mm

diam

eter

bars

are

used

.

Let�s

verif

yth

ead

opte

dde

sign

met

hod

inor

der

toev

aluat

edits

prec

ision

.Th

efo

llow

ing

resu

ltsar

eob

tain

ed:

k w=

1,s=

5310

/(50

0á10

00)=

0.01

062

2 nn

1000

y15

5310

437

y0

22 n

ny

159.

3y69

614

0

2ny

79.6

579

.65

6961

419

5.9

mm

,=

0.39

18

n

32

94

y10

0019

5.9

I15

5310

437

195.

97.

1310

mm

3

6s

9

437

195.

915

600

1030

4M

Pa7.

1310

Fig.

7.8.

Desi

gned

sectio

ns.

k w=

1k

w0.

3m

m

s=29

0M

Pa

k w=

2/3

kw

0.2

mm

s=22

1M

Pa

k w=

1/3

kw

0.1m

m

s=

140

MPa

Page 55: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-15

Tabl

eof

Cont

ent

The

low

estv

alue

for

hast

obe

chos

enbe

twee

n

=2.

5(1�

0.87

4)=

0.31

5;=

(1�

0.39

18)/

3=

0.20

27

Then

s,cr

0.20

270.

0106

20.

63.

086

115

63.1

1M

Pa0.

0106

20.

2027

k5

304

63.1

10.

2027

w1

3.4

500.

1726

0.30

6m

m30

40.

0106

22

10

k w=

2/3

,s=

69.0

3/

(50á1

00)=

0.01

38

2 nn

1000

y15

6903

437

y0

22 n

ny

207.

1y

9049

80

2ny

103.

510

3.5

9049

821

4.6

mm

,=

0.42

92

n

32

94

y10

0021

4.6

I15

6903

437

214.

68.

4110

mm

3

6s

9

437

214.

615

600

1023

8M

Pa8.

4110

=(1�

0.42

92)/

3=

0.19

03

s,cr

0.19

030.

0138

0.6

3.08

61

1553

.31

MPa

0.01

380.

1903

k5

238

53.3

10.

1903

w1

3.4

500.

1726

0.21

3m

m2

1023

80.

0138

k w=

1/3,

s=

111.

51/

(50á1

00)=

0.02

23

2 nn

n10

00y

1595

5843

7y

1593

385

y0

22 n

ny

334.

5y

1437

040

2ny

167.

216

7.2

1437

0424

7.1m

m,

=0.

494

n

32

29

4y

1000

247.

1I

1595

5843

724

7.1

1515

9338

524

7.1

1.06

10m

m3

6s

9

437

247.

115

600

1016

0M

Pa1.

0610

=(1�

0.49

4)/

3=

0.16

87

EC2�

wor

ked

exam

ples

7-16

Tabl

eof

Cont

ent

s,cr

0.16

870.

0223

0.6

3.08

61

1541

.78

MPa

0.02

230.

1687

k5

160

41.7

80.

1687

w1

3.4

500.

1726

0.12

mm

210

160

0.02

23

The

obta

ined

valu

esar

ein

good

agre

emen

twith

thos

eev

alua

ted

with

inth

ede

sign.

The

valu

esfr

omth

eve

rific

atio

nar

esli

ghtly

large

rbe

caus

eof

the

fact

that

inth

eco

nsid

ered

sect

ion

the

inte

rnal

driv

elev

erar

mis

low

erth

anth

eap

prox

imat

edva

lue

0.9d

assu

med

inth

eap

prox

imat

edde

sign

proc

edur

e.In

fact

,bein

gh 0

/dth

ead

imen

siona

llev

erar

min

units

ofef

fect

ive

heig

htd,

inth

eth

ree

case

we

have

k w=

1h 0

/d=

(43.

70�

19.5

9/3)

/43

.70

=0.

85k w

=2/

3h 0

/d=

(43.

70�

21.4

6/3)

/43

.70

=0.

836

k w=

1/3

h 0/d

=[(1

8á16

0á18

.99

+3á

160á

13.7

92 /18.

99)/

(18á

160

+3á

160á

13.7

9/18

.99)

+

+2/

3á24

.71]

/43

.70

0.8

Let�s

rem

ark

that

the

pres

ence

ofa

com

pres

sed

rein

forc

emen

tis

high

lyre

com

men

ded

tom

ake

duct

ileth

ese

ctio

nin

the

ultim

ate

limit

stat

e.Th

ere

info

rcem

enti

ncre

ase

the

leve

rarm

ofth

ese

ctio

nre

duci

ngth

edi

ffere

nce

betw

een

the

appr

oxim

ated

valu

esan

dth

ose

com

ing

from

the

verif

icat

ion.

The

appr

oxim

ated

met

hod

prev

ious

lydi

scus

sed

can

besu

cces

sful

lyap

plie

din

the

desig

nof

the

ultim

ate

crac

kst

ate.

The

obta

ined

resu

ltsar

ere

porte

din

the

Tabl

es7.

1an

d7.

2an

dth

eyar

esh

own

inFi

gure

7.9.

Tabl

e7.

3an

dFi

gure

7.10

repo

rtnu

mer

icalv

alues

and

grap

hsfo

rth

em

axim

aldi

amet

eran

dth

ere

quire

dre

info

rcem

ent

expr

esse

das

afu

nctio

nof

fixed

valu

esfo

rs.

Stat

ing

asu

itabl

epr

ecisi

onfo

rthe

appr

oxim

ated

met

hod,

thos

eva

lues

are

evalu

ated

usin

gth

e(7

.16)

(7.1

4).

Tab

le7.

1.A

ppro

xima

tedm

ethod

.T

able

7.2.

Exa

ctme

thod

.

wk(m

m)

As(m

m2 )

s(M

Pa)

h 0/d

As(m

m2 )

wk

(mm

)s(M

Pa)

h 0/d

0.1

1115

114

00.

911

151

0.12

016

00.

811

0.2

6903

221

0.9

6903

0.21

323

80.

836

0.3

5310

190

0.9

5310

0.30

630

40.

85

Fig.

7.9.

Com

paris

onbe

tween

thee

xact

and

appr

oxim

ated

meth

ods.

Page 56: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-17

Tabl

eof

Cont

ent

Tab

le7.

3.A

ppro

xim

ated

meth

od�

Dete

rmin

ation

ofma

ximu

mdi

amete

r.

wk

=0.

1m

m(A

)w

k=

0.2

mm

(B)

w k=

0.3

mm

(C)

s(M

Pa)

max

(mm

)A

s(m

m2 )

s(M

Pa)

max

(mm

)A

s(m

m2 )

s(M

Pa)

max

(mm

)A

s(m

m2 )

137

3011

111

214

3070

0128

030

5430

140

2611

151

221

2669

0329

026

5310

145

2010

486

233

2065

0830

920

4910

149

1610

205

243

1662

4532

516

4672

156

1097

5026

110

5816

355

1042

82

Fig.

7.10

.Dia

grams

forM

axim

aldi

amete

r(m

ax)�

Meta

larea

(As)�

Steel

tensio

n(

s).

EC2�

wor

ked

exam

ples

7-18

Tabl

eof

Cont

ent

EX

AM

PL

E7.

6V

erifi

catio

nof

limit

stat

eof

defo

rmat

ion

Eva

luat

eth

eve

rtica

ldisp

lacem

enti

nth

em

id-s

pam

ofth

ebe

amin

Figu

re7.

11w

ithco

nsta

nttra

nsve

rsal

sect

ion

repr

esen

ted

inFi

gure

7.12

Fig.

7.11

.defl

ected

beam

,defo

rmat

ionlim

itsta

te.Fi

g.7.

12.T

rans

versa

lsect

ion.

Ass

ume

the

follo

win

gva

lues

fort

hem

ainpa

ram

eter

s

f ck=

30M

Pa;g

+q=

40kN

/m;g

=2q

;l=

10m

;As=

3164

mm

2(7

24);

and

solv

eth

epr

oblem

first

lyin

acu

mul

ativ

ew

ay,s

tatin

ge

=E s

/Ec=

15.

Refe

rrin

gto

the

stag

eI,

asin

dica

ted

inFi

gure

7.13

,*

2

* G

32

*2

94

I

9*

73

i

A70

050

015

3164

3974

60m

m70

050

035

015

3164

650

y38

5.8m

m39

7460

500

700

I50

070

035

.815

3164

650

385.

818

.05

10m

m12 18.0

510

W5.

745

10m

m70

038

5,8

From

Tabl

e[3

.2-E

C2]

we

get

2 3ct

mf

0.30

302.

9MPa

and

then

the

crac

king

mom

entr

esul

ts*

76

crct

mi

Mf

W2.

95.

745

1010

166.

6kN

m

Cons

ider

ing

the

who

leap

plied

load

then

2

max

4010

M50

0kN

m8

max cr

M50

03

M16

6.6

Fig.

7.13

.Se

ction

atsta

geI.

Inth

est

age

II,a

srep

orte

din

Figu

re7.

13,

Page 57: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-19

Tabl

eof

Cont

ent

2 nn

2 nn

2n

32

*10

4II

y50

015

3164

650

y0

2y

189.

84y

1233

960

y94

.92

94.9

212

3396

269m

m

269

I50

015

3164

650

269

1.01

10m

m3

then

c=18

.05/

10.1

3=1.

78

Fig.

7.14

.Sect

ionat

stage

II.

The

evalu

atio

nof

the

mid

dle-

spam

disp

lacem

entc

anbe

easil

yob

tain

edus

ing

the

relat

ion

(7.1

)he

reex

pres

sed

as

II

vl2

vl

2v

l2

1v

l2(7

.20)

whe

rev I

isth

edi

splac

emen

tca

lcul

ated

inth

efir

stst

epan

dv(

l/2)

the

incr

ease

ofth

edi

splac

emen

tits

elfc

ause

dfr

omth

ecr

acki

ng,t

hatc

anbe

expr

esse

dfo

rsym

met

ryre

ason

11

11

22

Mm

axcr

22

M2

cI

max

fM

Mz

v2

c1

fg

dd

,=

2E

IM

gl

(7.2

1)

whe

reE

cis

assu

med

tobe

Ec

=E

s/15

inag

reem

entw

ithth

ein

trodu

ced

stat

emen

tfo

rth

epa

ram

eter

e,.

Def

inin

gth

epa

ram

eter

=M

max

/Mcr

and

cons

ider

ing

that

f M(

)=

/2,g

()

=4(�

2 ),th

eeq

uatio

n(7

.21)

isw

ritte

nas 1

1

11

22

3m

ax2

22

cI

Md

vc

14

d2

EI

41

(7.2

2)

Calcu

latin

gth

ein

tegr

also

nth

erig

htsid

eof

the

equa

tion

we

finall

yob

tain

24

3m

ax1

11

2c

I

M5

4v

c1

ln2

12

EI

483

4(7

.23)

The

absc

issa

1,w

here

the

crac

ked

part

ofth

ebe

amst

art,

isgi

ven

solv

ing

the

equa

tion

2cr

11

max

M1

4M

(7.2

4)

EC2�

wor

ked

exam

ples

7-20

Tabl

eof

Cont

ent

and

then

11

11

2(7

.25)

Fina

lly,c

onsid

erin

gth

at2

max

Ic

I

M5

v48

EI

(7.2

6)

The

(7.2

0)is

expr

esse

das

24

3m

ax1

11

2c

I

M5

484

12v

1c

11

ln2

12

48E

I5

35

(7.2

7)

Ifth

eva

lue

ofc

prev

ious

lyca

lculat

edis

inse

rted

inth

e(7

.27)

stat

ing

=1

and

lettin

gch

angi

ngin

the

rang

e1

,we

obta

inth

ecu

rves

repo

rted

inFi

gure

7.15

,tha

tsho

was

the

incr

ease

ofth

era

tiom

eans

ade

crea

sefo

r1

and

the

incr

ease

ofv(

l/2)

asa

cons

eque

nce

ofa

large

rcra

cked

part

ofth

ebe

am.

Inth

esa

me

way

,aco

ncen

trate

dlo

adQ

=20

0kN

,pro

duci

ngth

esa

me

max

imal

mom

enti

nth

em

id-s

pam

sect

ion,

lead

sto

the

follo

win

gex

pres

sion

fort

hese

ctio

ndi

splac

emen

t2

3m

ax1

1*

2c

I

Ml

3v

1c

11

81

22

12E

I(7

.28)

inth

isca

se2

1m

axc

I

vM

12E

I(7

.29)

1=1/

(2).

(7.3

0)

The

corr

espo

ndin

gcu

rves

are

repo

rted

inFi

gure

7.15

.We

obse

rve

asth

edi

spla

cem

ents

inth

etw

oca

ses

ofdi

strib

uted

and

conc

entra

ted

load

are

resp

ectiv

ely

0.93

and

0.88

ofth

edi

splac

emen

tca

lcul

ated

inth

est

age

II.F

urth

erm

ore,

for

the

sam

eM

max

,the

disp

lacem

enti

nca

seof

conc

entra

ted

load

resu

ltsto

belo

wer

beca

use

the

linea

rtre

ndof

the

relat

ive

bend

ing

mom

ent

isas

soci

ated

toa

small

erre

gion

ofth

ecr

acki

ngbe

amw

ithre

spec

tto

the

case

ofdi

strib

uted

load

,tha

tisc

hara

cter

ized

bya

para

bolic

diag

ram

ofth

ebe

ndin

gm

omen

ts.

Fig.

7.15

.Dia

gram

sfor

v/v 1

,1-

.Th

esa

me

prob

lem

sca

nbe

solv

edin

age

nera

lized

form

eval

uatin

gnu

mer

icall

yth

edi

splac

emen

tfo

llow

ing

the

proc

edur

eex

pres

sed

in(1

1.51

).In

this

way

,it

ispo

ssib

leth

eev

aluat

ion

the

defo

rmat

ion

ofth

ew

hole

beam

,var

ying

z.T

here

sult,

for

adi

strib

uted

load

Page 58: Beam Model Calculation

EC2�

wor

ked

exam

ples

7-21

Tabl

eof

Cont

ent

and

for

=3,

isre

porte

din

Figu

re7.

6,w

here

grap

hsre

fer

toa

20fo

lder

sdi

visio

nfo

rth

ecr

acki

ngpa

rtof

the

beam

.Rem

ark

asth

eco

mm

itted

erro

rin

the

evalu

atio

nof

the

mid

-spa

mde

flect

ion,

asob

tain

edco

mpa

ring

the

valu

esin

Figu

re7.

15an

dFi

gure

7.16

,is

abou

t4%

.In

parti

cular

,int

rodu

cing

the

num

eric

alva

lues

inth

e(7

.26)

(7.2

9)an

dus

ing

the

resu

ltsin

Figu

re11

.25,

we

have

fort

hem

id-s

pam

disp

lacem

ent:

Dist

ribut

edlo

ad6

8

15

9

550

010

1015

v21

.64m

m2

482

1018

.05

10

v1.

6521

.64

35.7

1mm

2

a)Co

ncen

trate

dlo

ad6

8

15

9

150

010

1015

v17

.31m

m2

122

1018

.05

10

v1.

5617

.31

27.0

0mm

2

Fig.

7.16

.Defo

rmat

ionin

thes

tage

I(a)

,disp

lacem

enti

ncrea

seca

used

byth

ecra

ckin

g(b)

And

total

defor

mat

ion(c)

.

EC2�

wor

ked

exam

ples

7-22

Tabl

eof

Cont

ent

Page 59: Beam Model Calculation

EC2�

wor

ked

exam

ples

11-1

Tabl

eof

Cont

ent

SEC

TIO

N11

.LIG

HT

WE

IGH

TC

ON

CR

ET

E–

WO

RK

ED

EX

AM

PLE

S

EX

AM

PL

E11

.1[E

C2

Cla

use

11.3

.1�

11.3

.2]

The

crite

riafo

rdes

ign

ofth

ech

arac

teris

ticte

nsile

stre

ngth

(frac

tile

5%an

d95

%)a

ndof

the

inte

rsec

ting

com

pres

sive

elas

ticm

odul

efo

rlig

htco

ncre

tear

esh

own

belo

w,

inac

cord

ance

with

the

instr

uctio

nsof

para

grap

hs11

.3.1

and

11.3

.2of

Euro

code

2.Te

nsile

stren

gth

The

aver

age

valu

eof

sim

ple

(axi

al)t

ensil

est

reng

th,i

nla

ckof

dire

ctex

perim

enta

tion,

can

beta

ken

equa

lto:

-for

conc

rete

ofcl

ass

LC50

/55

f lctm

=0,

30f lc

k2/3

1

-for

conc

rete

ofcl

ass>

LC50

/55

f lctm

=2,

12ln

[1+(

f lcm/1

0)]

1

Whe

re:

1=

0,40

+0,6

0/2

200

=up

perl

imit

valu

eof

the

conc

rete

dens

ity,f

orth

eco

rresp

ondi

ngde

nsity

clas

sexp

ress

edin

kg/m

3 ;

f lck

=va

lue

ofth

ech

arac

teris

ticcy

lindr

icco

mpr

essiv

estr

engt

hin

MPa

.f lc

m=

valu

eof

the

aver

age

cylin

dric

com

pres

sive

stre

ngth

inM

Pa.

The

char

acte

ristic

valu

esof

sim

ple

tens

ilestr

engt

h,co

rresp

ondi

ngto

fract

iles

0,05

e0,

95,

can

beta

ken

equa

lto:

fract

ile5%

:f lc

tk,0

,05

=0,

7f lc

tm

fract

ile95

%:

f lctk

,0,9

5=

1,3

f lctm

Inte

rsec

ting

com

pres

sive

elas

ticm

odul

eIn

lack

ofdi

rect

expe

rimen

tatio

n,th

ein

ters

ectin

gco

mpr

essiv

eel

astic

mod

ule

at28

days

,w

hich

can

beus

edas

anin

dica

tive

valu

efo

rde

sign

ofth

ede

form

abili

tyof

struc

tura

lm

embe

rs,c

anbe

estim

ated

byth

eex

pres

sion:

0,3

lcm

lcm

Ef

E22

000

10[M

Pa]

whe

re: f lcm

=va

lue

ofth

ecy

lindr

icav

erag

eco

mpr

essi

vest

reng

thin

MPa

;2

E22

00;

=up

perl

imit

valu

eof

the

conc

rete

dens

ity,f

orco

rresp

ondi

ngde

nsity

clas

sin

kg/m

3 .The

resu

ltsof

calc

ulat

ion

ofth

etw

oab

ove-

men

tione

dm

echa

nica

lfe

atur

esar

esh

own

and

com

pare

din

the

follo

win

gta

ble,

for

two

diff

eren

tty

pes

oflig

htco

ncre

tes

and

for

the

corre

spon

ding

ordi

nary

conc

rete

sbel

ongi

ngto

the

sam

estr

engt

hcl

asse

s.

EC2�

wor

ked

exam

ples

11-2

Tabl

eof

Cont

ent

Tabl

e11

.1

Con

cret

ety

pe1

Con

cret

ety

pe2

Lig

htO

rdin

ary

Ligh

tO

rdin

ary

f lck

[MPa

]35

60[k

g/m

3 ]16

5024

0020

5024

00f lc

m[M

Pa]

4368

10,

850

--0,

959

--E

0,56

3--

0,86

8--

f ctm

[MPa

]2,

73,

24,

24,

4f ct

k;0,

05[M

Pa]

1,9

2,2

2,9

3,1

f ctk;

0,95

[MPa

]3,

54,

25,

45,

7E l

cm[M

Pa]

1916

834

077

3395

039

100

Page 60: Beam Model Calculation

EC2�

wor

ked

exam

ples

11-3

Tabl

eof

Cont

ent

EX

AM

PL

E11

.2[E

C2

Cla

use

11.3

.1�

11.3

.5�

11.3

.6�

11.4�

11.6

]

The

max

imum

mom

entt

hatt

here

info

rced

conc

rete

sect

ion

ofgi

ven

dim

ensio

ns,m

ade

ofty

pe1

light

wei

ghtc

oncr

ete,

desc

ribed

inth

epr

evio

usex

ampl

e,is

able

tow

ithst

and

whe

nth

ere

info

rcem

ents

teel

achi

eves

the

desi

gnel

astic

limit.

The

dim

ensi

onso

fthe

sect

ion

are:

b=30

cm,h

=50c

man

dd=

47cm

.Th

ese

ctio

nin

ques

tion

issh

own

inFi

g.11

.1to

geth

erw

ithth

estr

ain

diag

ram

rela

ted

toth

efa

ilure

mod

ere

calle

d,w

hich

impl

ies

the

simul

tane

ous

achi

evem

ent

ofm

axim

umco

ntra

ctio

nsid

eco

ncre

tean

dof

the

stra

inco

rresp

ondi

ngto

the

desi

gnyi

eld

stres

sof

the

tens

ione

dre

info

rcem

ents

teel

.In

case

one

choo

ses,

like

inth

epr

evio

usex

ampl

e,to

use

the

bilin

eard

iagr

amto

calc

ulat

eth

eco

mpr

essiv

est

reng

thon

conc

rete

,the

limits

ofstr

ain

byco

mpr

essi

onha

veva

lues

lc3

=1,

75�

and

lcu3

=3,

51

=2,

98�

.

The

desig

nstr

ain

corre

spon

ding

tost

eely

ield

ing,

forf

yk=

450

MPa

,is

yd=

f yd/(1

,15

xE s

)=

450/

(1,1

5x

2000

00)

=1,

96�

.The

dist

ance

ofth

ene

utra

lax

isfro

mth

eco

mpr

esse

dup

pere

dge

isth

eref

ore

x=

28,3

cm.

Two

area

scan

bedi

sting

uish

edin

the

com

pres

sed

zone

:the

first

one

isco

mpr

ised

betw

een

the

uppe

redg

ean

dth

ech

ord

plac

edat

the

leve

lwhe

reth

eco

ntra

ctio

nis

lc3

=1,

75�

.The

com

pres

sive

stres

sin

itis

cons

tant

and

itis

equa

lto

f lcd

=0,

85f lc

k/c

=19

,8M

Pa;t

hese

cond

rem

aini

ngar

eais

the

one

whe

reco

mpr

essio

non

conc

rete

linea

rlyde

crea

ses

from

the

valu

ef lc

dto

zero

inco

rresp

onde

nce

ofth

ene

utra

laxi

s.Th

ere

sulta

ntof

com

pres

sion

forc

esis

plac

edat

adi

stanc

eof

arou

nd10

,5cm

from

the

com

pres

sed

end

ofth

ese

ctio

nan

dis

equa

lto

C=

1185

kN.

For

the

cond

ition

ofeq

uilib

rium

the

resu

ltant

ofco

mpr

essio

nsC

iseq

ual

toth

ere

sulta

ntof

tract

ions

T,to

whi

chco

rres

pond

sa

steel

sect

ion

As

equa

lto

As

=T/

f yd=

3030

mm

2 .The

arm

ofin

tern

alfo

rces

ish�

=d�

10,5

cm=

36,5

cm,f

rom

whi

chth

eva

lue

ofth

em

omen

tres

istan

ceof

the

sect

ion

can

even

tual

lybe

calc

ulat

edas

MR

d=

1185

x0,

365

=43

2,5

kNm

.

Fig

.11.

1D

efor

mat

ion

and

tens

ion

diag

ram

ofr.c

.sec

tion,

build

upw

ithlig

htwe

ight

conc

rete

(f lck

=35

MPa

,=

1650

kg/m

3 ),fo

rcol

laps

eco

nditi

onin

whi

chm

axim

umre

sist

ing

bend

ing

mom

enti

sre

ache

dwi

thre

info

rcem

enta

tela

stic

desig

nlim

it.

EC2�

wor

ked

exam

ples

11-4

Tabl

eof

Cont

ent