tushar final ppt

7/28/2019 Tushar Final Ppt

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SEISMIC EVALUATION AND RETROFITTINGOF RC FRAME BUILDINGS WITH OPEN

GROUND STOREY

1

BY : TUSHAR V. PAJGADE

(M.TECH. STRUCTURAL DYNAMICS)

PROJECT GUIDE

DR. RATNESH KUMAR

ASSTT. PROF. APPLIED MECHANICS DEPT.

VISVESARAYA NATIONAL INSTITUTE OF TECHNOLOGY, NAGPUR

SEMINAR

ON


2/98

Introduction

Literature Review on damages of RC frame

building

Literature Review on Retrofitting

Objective

Methodology

Scope of work

Comparative study

Modelling of masonary infill

2

OUTLINE OF PRESENTATION


3/98

Pushover analysis of G+3, G+7

& G+15 storey building

Determination of performance point

Determination of Ductility

Comparisons of inter story drift ratio

Retrofitting techniques used

References

3


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4

INTRODUCTIONOPEN GROUND STOREY

Open ground storey is a storey in which ground storey is

constructed without infilled walls

In many countries its common practice to construct RC frame

with OGS.

Also local municipal / building bylaw direct same for solving

parking problem.

Photo from eq tips (Murthy CVR)


5/98

5

Behaviour of Improperly Designed RC Frame

Buildings

Open ground storey damages

Infill wall damages

National and International code provision forinfill walls

Retrofitting strategies

Retrofitting techniques

Literature Review on


6/98

6

Brittle failure (Photo from: Housner &

Jennings, Earthquake Design Criteria,

EERI, USA)

Shear failure of RC columns due

to short column effect (over

view of chi chi eq 1999)

Behaviour of Improperly Designed RC Frame

Buildings


7/987

Weak column strong beam

failure three-story primary

school in Gedikbulak village

after collapse (photos: Erdil)

Turkey Earthquake

Dislodged Column due to Soft

ground Floor effect (1999 Athens

Earthquake)


8/988

During Turkey earthquake of 17 august 1999

In Kocaeli city, 41317 RC frame building were heavily

damaged or collapsed, 46961 were moderately damaged

and 51233 were slightly damaged. In Sakarya city, 29844 RC frame building were heavily

damaged or collapsed, 22170 were moderately damaged

and 26772 were slightly damaged.

Takashi, et al. (2002)

Takashi K., Fumitoshi K., Yoshiaki N., Quickinspection manual for damaged reinforced

concrete building due to earthquake 2002

(June 25, 2012)
http://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdfhttp://www.mlit.go.jp/sogoseisaku/inter/keizai/gijyutu/pdf/risk_judge_j_08_1.pdf


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After 2010 Haiti earthquake eberhard, et al. survey 107building in port-au-prince downtown indicated that

28% had collapsed and 33% were damaged enough to

require repairs.

Another survey held on Leogane city of 52 buildings,

found that 62% had collapsed and another 31% required

repairs.

Eberhard, et al. (2010)

Eberhard Marc O.,Justin M., Walter M., Glenn J. Rix, USGS/EERI Advance

Reconnaissance team report v. 1.1 February 23, 2010

(July 15, 2012)
http://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdfhttp://pubs.usgs.gov/of/2010/1048/of2010-1048.pdf


10/9810

Bhuj earthquake (India)

Damages not only related to epicentre.

In Ahmadabad 75 RCC building collapsed and

thousands others damaged.Clearly demonstrating the seismic vulnerability of this

type of design

Jaiswal, et al.(2003)

Jaiswal K.S., Sinha, R., Goyal, A., World housing encyclopaedia report Country India

Primary Reviewer: Craig Comartin 2003

(July15, 2012)
http://www.eeri.org/lfe/pdf/india_reinforced_concrete_frame.pdfhttp://www.eeri.org/lfe/pdf/india_reinforced_concrete_frame.pdf


11/9811

Taiwan government enacted a law in 1984 to encourage

contractor to build OGSDemanded 1st floor height at least 5m.

In return they were awarded with extra floor area.

And Result !

Damages of open ground storey

Tung and George(2003)

Chi Chi earthquake 1999 (photo from World Housing Encyclopedia Report)

Tung Su. Chi, George C. Yao, World housing encyclopaedia Country Taiwan, Primary Reviewer:

Durgesh Rai 2003`( June 26, 2012)
http://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdfhttp://www.eeri.org/lfe/pdf/taiwan_high_rise.pdf


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Murty (2005)

OGS adverse effect is observed during bhuj earthquake.

In Ahmadabad alone has about 25,000 five-storey buildings

and about 1,500 eleven-storey buildings

100 RC frame buildings with open ground storeys are

collapsed totally.

Bhuj earthquake (photo from EQ tips)

Murty C.V.R., IITKBMTPC Earthquake Tips Learning Earthquake Design and Construction,

National Information Centerof Earthquake Engineering, IIT Kanpur, India, September 2005.


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Damages of Infilled wall

Corner crushing

Shear slip of wall

Toe crushing

Diagonal tension

Behavior of masonry infill walls

(photo from Klingner 1976)


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14

For RC frame without infill

For RC Frame with infill

IS CODE 1893:2002

Ta=0.075h0.75

4.3.6 Additional measures for masonry infilled frames

4.3.6.3 Irregularities due to masonry infills

4.3.6.4 Damage limitation of infills

5.9 Local effects due to masonry or concrete infills

6.10.3 Moment resisting frames with infills

EUROCODE 8

National and International Code provision

for Infill Walls


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15

Model infill wall as a strut

(Photo from FEMA)

FEMA-356 And ASCE-41

a=Width of equivalent diagonalcompression strut

For how to model & calculating equivalent stiffness

a= 0.175 (1 hcol ) -0.04 rinf

Where,


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16

Literature Review on Retrofitting

Retrofitting strategies

Retrofitting Techniques


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17

Repair: The process to regain original strength of a damage

or deteriorated structure is called as Repair.

Seismic Retrofitting: The process to enhance original

strength of a deficient or damaged structure and enabling it

to satisfactorily can perform its intended performance in

future seismic event is called seismic retrofitting.

Retrofitting StrategiesStiffness increase

Strength increase

Ductility increase

Mass reduction


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18


Typical load-displacement relationships for different strengthening

Techniques [Rodriguez et. al. (1991)]

Rodriguez, M. and Park, R. (1991),Earthquake Spectra, 7(3), 817-841.


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19

Different Retrofitting Techniques

1. Addition of shear wall

2. Addition of bracing

3. Jacketing

4. Friction dampers


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20

1. Addition of shear wall

Its an Effective method of increasing building strength and

stiffness

Can form an efficient lateral-force resisting system

With fulfilling functional requirements (ATC-40)

In Japan, from 1933 to 1975 about 85% case of retrofitting was

executed using shear walls [Rodriguez et al. (1991)]

[Murty, C.V.R. (2005). IITKBMTPC Earthquake Tips]

Shear wall in RC frame (Murthy EQ Tips)

Rodriguez, M. and Park, R. (1991), Repair and Strengthening of Reinforced Concrete Buildings for Seismic

Resistance,Earthquake Spectra, 7(3), 817-841.


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21

Adverse effect

If large number of shear wall added then it result in increase

in mass of the building

Increase in seismic forces also demand i.e., requirement ofstrength increases

It can effect into architectural impact through the loss of

windows

It require special foundation work which highly expensive as

it produces large overturning forces at their base

[Murty, C.V.R. (2005). IITKBMTPC Earthquake Tips]

Shear wall (Photo from Murthy, C.V.R. EQ tips)


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22

2. ADDITION OF BRACING

Increases stiffness, strength and ductility

Can construct with less disruption in building with verysmall loss of lights

Its very difficult to attach braces with frame in seismic

retrofitting.

a)Concentric bracingb)Eccentric bracingc)Post-tensioned steel bracing

d)Buckling restrained bracings


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(a) Concentric bracing (Lorant G. http://www.wbdg.org/resources/seismic_design.php>)

(b) Eccentric bracing (Kiymaz, G. )

(a) (b)


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24

Tsai, K.C., Lai, J.W., Hwang, Y.C., Lin, S.L., and Weng, C.H. (2004),Proc., 13th World

Conference of Earthquake Engineering, Vancouver, B.C., Canada.

(d-1) Schematic of BRBs or UBs (d-2) Typical types of BRBs [Tsai et al.; 2004]


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25

3. JACKETING

Jacketing adds both strength and stiffness to

structureIncreases cross section of member

Four types of jacketing

column jacketing

beam jacketing

column-beam joint jacketing

infill jacketing


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26

column jacketing

During 1970s earthquake many of the structural failures

due to inadequate shear strength and/or improper

spacing in confinement in concrete columns

Column jacketing improves strength and ductility andconverting strong-beam weak-column into strong-

column weak-beam mechanism (Choudhuri et al, 1992; Rodriguez

and Park, 1994; Bracci et al, 1997; Bush et al, 1990)

Jacketing of column (Photo from Famer group)


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27

4 FRICTION DAMPERS

Concept of Friction dampers

The Friction brake is widely used to extract kinetic energy from a

moving body as it is the most effective mean to dissipate energy.

It is an effective way to control seismic response of structure and

non structural damage.

It does not impact the foundation design, increase stiffness of the

frame until a certain shear level is reached, at which the dampers

can be set to slip.

Pall Friction Damper ( Photo from Golafshani. A. A and Gholizad.A 2009)

Golafshani, A. A., and Gholizad, A. (2009).J. Of Const. Steel Research 65(1), 180-187.


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28

Filistrault 1986

In 1985 a 3 storey frame equipped with friction-dampers was

tested on a shake table

An earthquake record with peak acceleration of 0.9g did notcause any damage to friction- damped braced frame. While

moment resisting frame & braced frame cause permanent

deformation

Aiken 19881987, a 9 storey three bay frame, equipped with friction

dampers, was tested on a shake table all members of the

friction- damped frame remained elastic for 0.84g

acceleration

while the moment- resisting frame would have yield at about0.3g acceleration

Filiatrault, A., Cherry, S.(1986).,Proc., 3rd conference on dynamic response of structure, ASCE,

Held at Los Angeles.

Aiken, I.D., Kelly, J.M., Pall, A.S. (1988)., Report No. UCB/EERC-88/17, Earthquake

Engineering Research Centre of the university of California, Berkeley, 1-7


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29

Disadvantage

It is very difficult to maintain its properties for longtime intervals

expensive and the selection of the appropriate slip

load is a critical


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30

Objective

To compare period, base shear, bending moment & shear

force of different frame like bare frame, infill frame, and

open ground storey frame by IS code & SAP model.

Performance of evaluation of these building by non-

linear static procedure.

Comparison of performance enhancement of these

building with different retrofitting techniques.

Identification of most suitable retrofitting techniques.


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Methodology

Generic plan of RC frame building selected.

Building modeled for different height i.e.,G+3, G+7, G+15

Selection of suitable modeling techniques in SAP

Modeling, design and comparison of base shear and period of

vibration of these building.

Performance of evaluation of these building by non-linear static

procedure.

Selection of retrofitting techniques & corresponding modeling

techniques in SAP.

Base on result will identify most suitable retrofitting techniques.


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32

Scope of work

Work will be limited to one type of limited plan and

three different height.


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33

Selection of Generic plan


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34

Period of vibration (with infill

wall)

in Sec.

Period of vibration

(without infill wall) in

Sec.

X-Direction Y-Direction X and Y-Direction

G+3 IS-1893 0.233 0.373 0.597

G+7 IS-1893 0.440 0.711 0.968

G+15 IS-1893 0.865 1.387 1.598

Period of vibration by IS 1893:2002 code Method

Comparison study


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Comparison of Modal mass Participation factor by RSA in SAP 2000

35

Types of

BuildingDirection Mode No. 1 2 3 Steps no.

Bare frame

X Modal Load

participation

factor

0.83228 0.0919 0.02403 1'4'7'

Y 0.81587 0.10453 0.03005 2'5'9'

Full infilled

X Modal Load

participationfactor

0.8828 0.07065 0.01303 3 7 11

Y 0.84107 0.09706 0.02433 146

Open Ground

storey

X Modal Load

participation

factor

0.92287 0.02662 0.0042 3610

Y 0.84133 0.09694 0.02422 147


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Comparison of Shear force and Bending moment in

member shown in below photo by RSA in SAP 2000

36

1

2

4

3

5

5

3

Bending


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37

Type of Building Location 2 Combinations Shear Forcein kN

Combinations

Bending

moment

kN.M.

Bare frame

Left side

Corner 1st

storey

column of

1st frame

1.5(DL+EQx) 30 1.5(DL+EQx) 61

Bare frame withinfill load only

1.5(DL+EQx) 60 1.5(DL+EQx) 122

Full infilled 1.5(DL+EQx) 33 1.5(DL+EQx) 83

Open Ground

storey1.5(DL+EQx)

56 1.5(DL+EQx)

211

Type of Building Location 1 Combinations Shear Force inkN

Combinations

Bending

moment

kN.M

Bare frame

Left side

Corner

ground

storey

column of

1st frame

1.5(DL+EQx) 41 1.5(DL+EQx) 83

Bare frame with

infill load 1.5(DL+EQx) 77 1.5(DL+EQx) 196


Open Ground

storey1.5(DL+EQx) 176 1.5(DL+EQx) 321

L tiShear Bending


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38

Type of BuildingLocation

3 CombinationsShear

Force in

kN

Combinations

Bending

moment

kN.M.

Bare frameLeft side

Corner 1ststorey

slab

Beam of

1st frame

1.5(DL+EQx) 59 1.5(DL+EQx) 110

Bare frame with

infill load only1.5(DL+EQx) 126 1.5(DL+EQx) 173


Open Ground

storey1.5(DL+EQX) 129 1.5(DL+EQX) 180

Type of BuildingLocation

5Combinations

Shear Force

in KNCombinations

Bending

moment

KN.M.

Bare frame

Left side

Corner

3rd storey

slab

beam of

1st frame

1.2(DL+LL+EQx) 32 1.2(DL+LL+EQx) 41

Bare frame withinfill load only

1.2(DL+LL+EQx) 39 1.5(DL+EQx) 55

Full infilled 1.5(DL+LL) 33 1.5(DL+LL) 30

Open Ground

storey

1.2(DL+LL+EQx) 28 1.2(DL+LL+EQx) 27


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Non linear static procedure

39

Capacity

Demand (displacement)

Performance

Analysis used in present study


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40

CapacityCapacity is representation of the structures

ability to resist the seismic demand.


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Demand (Displacement)

41

Demand is representation of the earthquake

ground motion.


42/98

Performance

Its dependent on a manner that the capacity is able to

handle the demand ORStructure must have the capacity to resist the demandof earthquake such that performance of the structure iscompatible with the objective of the design

42


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Pushover analysis

43

Different code have described pushover analysis

procedure, modelling & acceptable limits It generates capacity curve beyond the elastic

limit

Capacity Spectrum Method

Displacement Coefficient Method

Photo from ATC40


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Flow chart of Pushover analysis

44Flow chart of capacity spectrum method (Photo from ATC-40)


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45

Limitations

This analysis procedure consider onlyfirst mode shape of the Equivalent SDOF

system.

Predefined vertical distribution of the

load along height in one direction at atime


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46

MODELLING AND ANALYSIS PROCEDURE

Column member, coupled axial force and biaxial

bending moment hinges which are mention as P-

M2-M3 hinge.

Beam members uncoupled moment hinges mention

as M3.

IO,LS,CP are structural performance level

Force- Deformation behaviour of a typical RC member

N li d lli f M i fill


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47

Non linear modelling of Masonary infill

No special provision for auto hinge for axial member

given in SAP2000 V14.2.4So provide manual hinges properties from FEMA356


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48

Calculate yield forceVine=Ani x fvie (N)

Where,

Py = maximum allowable yield force,

Vine = a design shear force,

Ani = a area of strut,

Fvie = a expected shear strength of masonry infill,


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Where,

Astrut = Area of strut,

Eme = Expected elastic modulus of masonry in

compression,

Linf = Length of infill,hinf = Height of infill,

= Angle between infill diagonal and horizontal

axis,

tinf = thickness of infill,

ESW = Equivalent strut width.

Nonlinear properties of infill


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50

Infill name

Yield

ForceDisplacement control parameter Acceptance Criteria

Fy (kN) B C D, E LS CP

S-J 261.80 0 0.083 0.083 0.063 0.083S-K 231.66 0 0.089 0.089 0.069 0.089

S-L 421.04 0 0.026 0.026 0.016 0.026

S-M 260.84 0 0.083 0.083 0.063 0.083

S-N 230.58 0 0.089 0.089 0.069 0.089

p p

(Photo from FEMA 356)


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51

Nonlinear properties of axial hinge to be filled in SAP


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52

0

2000

4000

6000

8000

10000

12000

14000

0 0.1 0.2 0.3 0.4

Baseshearin

kN

Displacement in m

full infill

OGS

Bare

frameB- IO- LS- CP- DBE- MCE-

Pushover curve of G+3 building in X - direction


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0

2000

4000

6000

8000

10000

0 0.1 0.2 0.3 0.4

Basesh

earinkN

Displacement in m

Bare

frame

Infill

OGS

B- IO- LS- CP- DBE- MCE-

Pushover curve of G+3 building in Y- direction


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54

0

3000

6000

9000

12000

15000

18000

21000

0 0.1 0.2 0.3 0.4 0.5

Baseshe

arkN

Displacement in m

Bare

frame

Full

infill

OGS


Pushover curve of G+7 building in X- direction


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55

0

2000

4000

6000

8000

10000

12000

0 0.1 0.2 0.3 0.4 0.5 0.6

BaseshearinkN

Displacement in m

Bare

frame

Full

infill

OGSB- IO- LS- CP- DBE- MCE-



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56

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

0 0.2 0.4 0.6 0.8

Baseshear

inkN

Displacemnt in m

Full

infill

OGS

Bare


Pushover curve of G+15 building in X- direction


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57

0

1000

2000

3000

4000

5000

6000

7000

0 0.1 0.2 0.3 0.4 0.5 0.6

Basesheari

nkN

Displacementi in m

Full

infill

OGS

Bare



Bi Linear izat ion of curve


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58

Bi-Linear izat ion of curve

(Photo from FEMA 356)

Ductility in X-Direction


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59

G+3 StoryDuctility

= u/yG+7 Story

Ductility

= u/yG+15 Story

Ductility

= u/y

Bare

frame

Fy = 4300

5.214Bare

frame

Fy = 9800

4.273Bare

frame

Fy = 11997

3.02y = 70mm y =110mm y =245mm

Fu = 4486 Fu = 10000 Fu = 11997

u = 365mm u =470mm u =740mm

Full

infilled

Fy = 6556

1Full

infilled

Fy =16000

5.571Full

infilled

Fy = 17100

2.4y = 20mm y = 70mm y =150mm

Fu = 6556 Fu =18388 Fu = 19118

u = 20mm u =390mm u =360mm

Open

ground

story

Fy = 5400

1.6

Open

ground

story

Fy =15200

2

Open

ground

story

Fy = 14000

2y = 30mm y = 80mm y =125mm

Fu = 5811 Fu =16633 Fu = 17346

u = 48mm u =160mm u =250mm

Ductility in Y Direction


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G+3 StoryDuctility

= u/yStory G+7

Ductility

= u/yStory G+15

Ductility

= u/y

Bare

frame

Fy = 4100

6.182Bare

frame

Fy = 7950

5.611Bare

frame

Fy = 2050

9.8y = 55mm y = 90mm y=100mm

Fu = 4927 Fu =8708 Fu = 2182

u = 340mm u =505mm u=980mm

Full

infilled

Fy = 6000

3Full

infilled

Fy = 8200

6.8Full

infilled

Fy = 6200

4.211y = 25mm y = 50mm y = 95mm

Fu = 7975 Fu = 10319 Fu = 7136

u = 75mm u=340mm u=400mm

Open

ground

story

Fy = 5800

4

Open

ground

story

Fy = 7900kN

5.727

Open

ground

story

Fy = 5400

2.167y = 30mm y = 55mm y = 90mm

Fu = 7552 Fu = 9963 Fu = 6200

u = 120mm u = 315mm u = 195mm

DETERMINATION OF PERFORMANCE POINT


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61

DETERMINATION OF PERFORMANCE POINT

Displacement modification method

t=C0C1C2Sa2

4 2x g

Target displacement

Comparison of Inter story drift ratio at MCE


62/98

p y

level

62Inter story Drift ratio in X-direction of 4 story at MCE

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0.00 0.50 1.00 1.50

Storyleve

l

Inter Story Drift Ratio (%)

Bare frame

Full

infilled

OGS


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63

0

1

2

3

4

5

0.00 0.20 0.40 0.60 0.80 1.00 1.20

Storylevel

Inter story Drift Ratio (%)

Bare

frame

Full

infilled

OGS

Inter story Drift ratio in Y-direction of 4 story at MCE


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64

0

1

2

3

4

5

6

7

8

9

0.00 0.20 0.40 0.60 0.80 1.00 1.20

Storylevel

Inter story drift Ratio (%)

OGS

Bare

frame

Full

infilled

Inter story Drift ratio in X-direction of 8 story at MCE


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65

0

1

2

3

4

5

6

7

8

9

0.00 0.20 0.40 0.60 0.80 1.00 1.20

Story

level


OGS

Bare frame

Full

infilled



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66

Inter story Drift ratio in X-direction of 16 story at MCE

0

2

4

6

8

10

12

14

1618

0.00 0.50 1.00 1.50

Storylev

el


Bare

frame

Full infill

OGS


67/98

67


0

2

4

6

8

10

12

14

16

18

0.00 0.50 1.00 1.50 2.00 2.50 3.00

Storylevel


Bare

frame

Full

infill

OGS



68/98


1) 2.5 times increasing design forces of

column & beam of a soft story

2) 2.5 times increasing design forces only in

column of a soft story

3) Friction dampers

4) Shear wall

68

Pushover curve of G+3 building retrofitting with 2.5


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69

0

2000

4000

6000

8000

10000

12000

14000

0 0.05 0.1 0.15 0.2

Baseshear(kN)

Displacement (m)

full

infill

OGS

2.5

column

2.5

column

& beam



column & beam in X- direction

2 5 Retrofitting column & beam


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70

2.5 Retrofitting column & beam

2.5 Retrofitting column only

P h f G+3 b ildi t fitti ith 2 5


71/98

71

0

2000

4000

6000

8000

10000

12000

0 0.05 0.1 0.15 0.2 0.25 0.3

Baseshear(kN)

Displacement (m)

Full infill

OGS

2.5

column

only

2.5

column

& beam



column & beam in Y- direction



72/98

72

0

3000

6000

9000

12000

15000

18000

21000

0 0.1 0.2 0.3 0.4 0.5

Baseshear(kN)

Displacement (m)

Fullinfill

OGS

2.5 RET

of Col in

X

2.5 col

& beam

in X


Pushover curve of G 7 building retrofitting with 2.5


Open ground


73/98

73

Open ground

story

2.5 Ret of column &

beam

2.5 Ret of column

only



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74

0

2000

4000

6000

8000

10000

12000

14000

0 0.1 0.2 0.3 0.4

Baseshear

(kN)

Displacement (m)

Full infill

OGS

2.5 Ret

col

2.5 Ret

col &

beam


g g




75/98

75

0

20004000

6000

8000

10000

12000

14000

16000

18000

20000

0 0.2 0.4 0.6 0.8

Baseshear(k

N)

Displacemnt (m)

Full

infill

OGS

2.5 Ret

of col

only

2.5 Ret

of col &

beam


g g


Open ground 2.5 Ret of column & 2.5 Ret of column


76/98

76

p g

story beam.5 et o co u

only



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77

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 0.1 0.2 0.3 0.4 0.5 0.6

Baseshear

(kN)

Displacementi (m)

Full

infill

OGS

2.5 Ret

column

2.5 Ret

column

& beam


g g


3 Friction dampers


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78

3. Friction dampers

Model as plastic (Wen)

Non linear properties

Yield strength (slip load)

Post yield stiffness ratio

Optimize position of dampers

Optimize yield strength

Pall Friction Damper( Photo from Golafshani. A. A and Gholizad.A 2009)

G+3 building retrofitting with friction dampers showing XZ


79/98

79

plane & 3D view


80/98

80

0

2000

4000

6000

8000

10000

12000

14000

0 0.05 0.1 0.15 0.2

Baseshear

(kN

)

Displacement (m)

full infill

OGS

Ret withFric

damp.


Pushover curve of G+3 building retrofitting with Friction

dampers in X-direction



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81

0

3000

6000

9000

12000

15000

18000

21000

0 0.1 0.2 0.3 0.4 0.5

Baseshea

rkN

Displacement in m

Full

infill

OGS

Ret

friction






82/98

82

0

3000

6000

9000

12000

15000

18000

21000

0 0.1 0.2 0.3 0.4 0.5 0.6

Baseshe

ar(kN)

Displacemnt (m)

Full infill

OGS

Ret Frict

dampers

B- IO- LS- CP- DBE - MCE -



Ductility Improve after retrofitting with Friction damper


83/98

Type of

building

G+3Ductility

= y/u

G+7Ductility

= y/u

G+15Ductility

= y/u

OGS

Retrofitti

ng withfriction

dampers

Fy = 9000

4.242

Fy = 15800

5.867

17100

3.268

y= 33mm y =75mm y=153mm

Fu = 10000 Fu = 18000 Fu =18800

u=140mm u =440mm u =500mm

Open

ground

story

Fy = 5400

1.600

Fy = 16633

2.000

Fy = 5400

2.000y= 30mm y = 80mm y=125mm

Fu = 5811 Fu = 15200 Fu = 5811

u =48mm u=160mm u=250mm

83

4 SHEAR WALL


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84

4. SHEAR WALL

Modelling of shear wall

Model shear wall as a wide column modelling.

To use auto hinge properties P-M2-M3.

Compare analysis and design of a wide column

model with thin shell model.


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85

Wide column model showing percentage of steel after addition of shear wall

Thin shell model showing percentage of steel after addition of shear wall.

G+3 building retrofitting with shear wall showing 3D view of

i i f h ll


86/98

86

position of shear wall

Optimization of position


87/98

87

0

2000

4000

6000

8000

10000

12000

14000

0 0.05 0.1 0.15 0.2

BaseshearinkN

Displacement in m

full infill

OGS

Shear

wall


Pushover curve of G+3 building retrofitting with shear wall in

X-direction

P h f G+7 b ildi t fitti ith h ll i


88/98

88

0

3000

6000

9000

12000

15000

18000

21000

0 0.1 0.2 0.3 0.4

BaseshearkN

Displacement in m

Full

infill

OGS

Ret

Shearwall


Pushover curve of G+7 building retrofitting with shear wall in

X-direction


89/98

89

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

0 0.2 0.4 0.6 0.8

Baseshearin

kN

Displacemnt in m

Full

infill

OGS

Ret.

Shearwall in-

X


Pushover curve of G+15 building retrofitting with shear wall

in X-direction

G+3 building retrofitted with shear wall in X direction


90/98

90

G+3 building retrofitted with shear wall in X-direction

showing hinges formation.

Comparison of ductility, yield force &ultimate force in open

ground story & retrofitting with shear wall model of different


91/98

91

Type of

buildingG+3

Ductility=

y/uG+7

Ductility=

y/uG+15

Ductility=

y/u

Retrofitting

with Shear

wall

Fy=11105

kN

7.118

Fy =14047

kN

7.174

Fy=17389

kN

7.071

y =17mm y = 46mm y=113mm

Fu = 12647

kN

Fu = 15403

kN

Fu =18964

kN

u=121

mm

u=330

mm

u=799

mm

Open ground

story

Fy = 5400

kN

1.600

Fy = 16633

kN

2.000

Fy = 5400

kN

2.000

y =30mm y = 80mm y=125mm

Fu = 5811

kN

Fu = 15200

kN

Fu = 5811

kN

u = 48mm u =160mm u=250mm

ground story & retrofitting with shear wall model of different

building in X- direction.

Conclusion


92/98

92

Conclusion

Considering ductility, strength capacity addition of shear wall

is best method of retrofitting, if properly analyze the building.

Ductility is increased up to 3.5 times compare to OGS.

Due to addition of friction damper ductility is increase 2.5

times compare to OGS.

In many cases, it could be difficult to achieve a single

retrofitting technique for attaining the desired performance of

buildings so combination of some of the above mentioned

techniques may be required

Future work

O i t id d i i fill S it bilit f th


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93

Openings were not considered in infills. Suitability of the

proposed strengthening schemes must be verified for masonary-

infilled frames with openings in walls.

Non linear dynamic analysis (time history analysis) is a best

method for analyzing the strengthening methods like friction

dampers.

The experimental work should be carried out on a reduced scale

three story with first story without infilled wall under gradually

increased cyclic lateral displacements to further verify theeffectiveness of proposed strengthening schemes.

Reference(contd.)


94/98

Aiken, I.D., Kelly, J.M., Pall, A.S. (1988). Seismic Response of a nine-storey

Steel frame with friction- damped cross-bracing, Report No. UCB/EERC-

88/17, Earthquake Engineering Research Centre of the university of

California, Berkeley, 1-7.Applied Technology Council ATC (1996). Seismic evaluation and retrofit of

concrete buildings. Rep. No. ATC-40, Applied Technology Council,

Redwood City, Calif.

Baboux, M., and Jirsa, J.O. (1990), Bracing System for Seismic Retrofitting,

J. Struct. Eng., ASCE, 116(1), 55-74.

Bracci, J.M., Kunnath, S.K., and Reihnorn, A.M., (1997). Seismic

performance and retrofit evaluation of reinforced concrete structures, J.

Struct. Eng., ASCE, 123(1), 3-10.

Bush, T.D., Jr., Talton, C.R., and Jirsa, J.O. (1990). Behavior of a structure

strengthened using reinforced concrete piers,ACI Struct. J., 87(5), 557-563.

Bush, T.D., Jones, E.A. and Jirsa, J.O. (1991a). Behavior of RC Frame

Strengthened Using Structural Steel Bracing, J. Struct. Eng.,

ASCE,117(4),1115-1126.

94

Computer and Structures, Inc. (CSI). SAP2000, version-14.2.4 Berkeley (CA,

Reference(contd.)


95/98

95

p , ( ) , y ( ,

USA): Computer and Structures, Inc., 2000.

Eberhard Marc O.,Justin M., Walter M., Glenn J. Rix, USGS/EERI Advance

Reconnaissance team report v. 1.1 February 23, 2010

Eurocode 8- Design of Structures for Earthquakes Resistance Part 1: GeneralRules, Seismic Actions and Rules for Buildings. Pr-EN 1998-1 Final Draft

Comit Europen de Normalisation. December 2003.

Federal Emergency Management Agency, Prestandard and Commentary for the

Seismic Rehabilitation of Buildings (FEMA 356). Federal Emergency

Management Agency, Washington, D.C.,USA 2000.

Golafshani, A. A., and Gholizad, A. (2009). Friction damper for vibration

control in offshore steel jacket platforms.J. of Const. Steel Research

65(1), 180-187.

Bush, T.D., Jr., Wyllie, L.A., Jr. and Jirsa, J.O. (1991b), Observations of Two

Seismic Strengthening Scheme for Concrete Frames,Earthquake Spectra,7(4), 511-902.

Reference(contd.)


96/98

96

Klingner R.Y., Bertero V. Infilled frames in earthquake-resistant construction,

University of California, Berkeley, Report No.EERC 76_32, December;

1976.

IS 1893 (part1)Criteria For Earthquake Resistance Design OfStructures(Fifth

Revison),BIS- New Delhi, India. 2002

Jaiswal K.S., Sinha, R., Goyal, A., World housing encyclopaedia report

Country India Primary Reviewer: Craig Comartin 2003.

Maheri, M.R., and Sahebi, A. (1997). Use of steel bracing in Reinforced

Concrete Frame,Eng.Struct., 19(12), 1018-1024.

Mortezaei1 A., Ronagh H. R., Kheyroddin A. and Ghodrati G. (2011).

Effectiveness of modified pushover analysis procedure for the estimation of

seismic demands of buildings subjected to near-fault earthquakes havingforward directivity.Struct. Design of Tall Spec. Build. 20, 679699.

Murty, C.V.R. (2005). IITKBMTPC Earthquake Tips Learning Earthquake

Design and Construction, National Information Center of Earthquake

Engineering, IIT Kanpur, India

Pall, A.S., Pall, R. (1991). Friction Dampers used for seismic control of new

Reference(contd.)


97/98

97

Pall, A.S., Pall, R. (1991). Friction Dampers used for seismic control of new

existing building in Canada,Proc. ATC 17-1, Seminar on seismic isolation,

passive energy dissipation and active control, San Francisco, 2, 675-686.

Rodriguez, M. and Park, R. (1991), Repairand Strengthening of Reinforced

Concrete Buildings for Seismic Resistance,Earthquake Spectra, 7(3),

817-841.

Rodriguez, M., and Park, R. (1994). Seismic load tests of reinforced concrete

columns strengthened by jacketing,ACI Struct. J., 91(2), 150-159.

Takashi K., Fumitoshi K., Yoshiaki N., Quick inspection manual for

damaged reinforced concrete building due to earthquake 2002

Tsai, K.C., Lai, J.W., Hwang, Y.C., Lin, S.L., and Weng, C.H. (2004).

Research and Application of Double-Core Buckling Restrained Braces

in Taiwan,Proc., 13th World Conference of Earthquake Engineering,

Vancouver, B.C., Canada.

Tung Su. Chi, George C. Yao, World housing encyclopedia Country Taiwan,

Primary Reviewer: Durgesh Rai 2003`

Th k Y


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Thank You

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