experimental earthquake engineering research in lnec · seismic engineering research...

SERIESSEISMIC ENGINEERING RESEARCH INFRASTRUCTURES

FOR EUROPEAN SYNERGIES

COMMISSION OF THE EUROPEAN COMMUNITIES

FP7- INFRASTRUCTURES-2008-1

SP4-Capacities

Experimental Earthquake

Engineering Research in LNECEngineering Research in LNEC

P. Candeias, A. Campos Costa, Ema Coelho

Earthquake Engineering Division - NESDE

National Laboratory for Civil engineering – LNEC, Lisbon

SERIES Workshop “Role of Research Infrastructures in Performance-based Earthquake Engineering” , Ohrid (MK), Sept 2., 2010

SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES

LNEC/NESDE Main activities

• Seismic action characterization studies, seismic hazard and seismic risk

• Seismic assessment of structures and study of techniques for seismic protection and rehabilitation

• Support to the development of seismic codes

• Technical and scientific support to National Authorities

SERIES Workshop “Role of Research Infrastructures in Performance-based Earthquake Engineering” , Ohrid (MK), Sept. 2, 2010

• Dynamic characterisation studies (in-situ Ambient Vibration Tests)

• Experimental research. Exploitation of the LNEC seismic testing facility (since 1995)

▫ European research projects (4th, 5th, 6th and 7th Framework Programmes of the EU)

▫ National research projects (FCT)

▫ LNEC funding


LNEC/NESDE STAFFResearch staff

• 3 senior researchers (2 civil engineers, 1 mechanical)

• 2 young researchers (geophysicists)

• 1 post-doc grant-holder (civil engineer)

• 3 research trainees (civil engineers), 2 PhD students, 1 MSc student

• 1 grant-holder, post-graduate and MSc student (civil engineer)

• temporary collaborators (exchange students, EU and National)


Technical staff (support to research activity)

• 2 1st class technicians (information systems and experimental activity)

• 4 lab technicians grant-holders, graduate students in civil engineering

Administrative staff

• 1 administrative

Support from Geotechnics Department and Scientific Instrumentation Centre


Experimental activity – EU projects

• ECOEST II – 1996-1999 – 5 User Groups

• NEFOREEE – 2001-2005

• ECOLEADER – 2002-2005 – 4 User Groups


• ECOLEADER – 2002-2005 – 4 User Groups

• SPEAR – 2002-2005

• PRECAST EC8 – 2003-2006

• SAFECAST – Started 2009

• SERIES – Started 2009


Experimental activity – National/LNEC

projects

• COMREHAB – 2000-2001

• MITRIS – 1999-2004


• MITRIS – 1999-2004

• FCT Stone Masonry – 2005-2008

• TLD – 2007/2009

• UMinho/LNEC Stone Masonry – 2008/2009

• QREN Reinforced Masonry – 2008/2009

• FCT Masonry enclosures – 2009/2010


LNEC seismic testing facility

• Main characteristics:

� Area ≈≈≈≈ 450m2


� Ceiling height 10m

� Movable height 8m

� Travelling crane 400kN

� Access gates 4.5m

http://www.lnec.pt/organizacao/de/nesde/



� Large 3D shaking table


� Large 3D shaking table

� Small 1D shaking table

�Reaction wall (in preparation)



� Max payload 40 ton

� Surface 4.6m by 5.6m


3D shake table


� Three independent orthogonal axes

� Displacements actively controlled

� Rotations passively restrained

� Frequency range from 0.1Hz up to 40Hz




1D shake table

� Max payload 6 tonnes

� Surface 3.2m by 2.2m


� Single horizontal/vertical axis

� Displacement actively controlled

� Frequency range from 0.1Hz up to 25Hz



Instrumentation

� Accelerometers

� Displacement Transducers


� Load Cells

� Strain Gauges

� Cameras for Test Documentation

� Cameras for Data Acquisition (planned for 2010, SERIES, NA1)



Signal Processing and Analysis Software

• Software LNEC-SPA

▫ Signal Generation

▫ Data acquisition

▫ Signal Processing

▫ System identification


▫ Visualization


Other experimental activities• In-Situ Ambient Vibration Tests (OMA)

▫ Output-only identification methods implemented in LNEC-SPA:

� Averaged Normalized Power Spectral Density (ANPSD)

� Frequency Domain Decomposition (FDD)

� Enhanced Frequency Domain Decomposition (EFDD)


� Enhanced Frequency Domain Decomposition (EFDD)


Performance Based Earthquake

Engineering (PBEE) - Concepts

• Seismic hazard levels


Tr = 72 years

Tr = 475 years

Tr = 2475 years

• Structural/non-structural performance levels

• Performance objectives


Case study #1:

Portuguese House of Parliament



� Goals of the Project:�Vulnerability assessment of the building

�Possible strengthening solutions

� Permanent monitoring system

� Emergency planning for disaster scenarios (evacuation plan)

Methodology:


�Methodology:�Dynamic characterization tests

�Numerical modeling (Dynamic and static non-linear models)

�Masonry characterization tests:

�Flat jack tests

�Ultrasonic and mechanical pulse velocity tests


Cloister

Passos Perdidos Hall

SenateAmphitheatre

NobleStaircase

AssemblyAmphitheatre


Office andMeeting RoomsLibrary

Noble Room

Main Entranceand Lobby

Amphitheatre


� Structural Characteristics:

�Geometry

� Length/Height ratio ≈ 4-5 (high stiffness)

�Materials

� Masonry walls, mainly tmax

=2.20m

� Wood pavements and roof trusses

≈6

5m

≈11

7m


� Wood pavements and roof trusses

� Steel beams

� Reinforced concrete pavements

�Discontinuities:

� Several reconstructions, repairs, upgrades

and change of usage type.

≈130m

hmax≈25m

(façade)

=> Very complex and heterogeneous structure!


� Test Setups

�Level 5 - Global

� 1 test setup covering all plan

� Façades

� 2 test setups in the left wing

� 1 test setup in the front façade

� 1 test setup in the rear façadey


� 1 test setup in the rear façade

� 1 test setup in the right wing

� Assembly Amphitheatre

� 3 test setups (level 5 + level 7 + roof)

� Senate Amphitheatre

� 2 test setups (level 3 and 5 + references and roof)

X


Vulnerable zones

1. Cloister

2.“Passos Perdidos” Hall

3. Main wall of the parliament


parliament

4.Left lateral wall of the corridor parallel to the amphitheatre

5.Right lateral wall of the corridor parallel to the amphitheatre

6.Lateral right wing


Partial analytical model

• LNEC Dams Department

• E.Bretas, P.Gomes, e V. Lemos


Parliament, mode in x direction

(3.2 Hz)Parliament, first mode in y

direction (4.0 Hz)

Senate, first mode in y

direction (3.5 Hz)


� Non-linear vulnerability analysis

� Discrete Element – DE 3DEC-LNEC (V.Lemos)


� 1º Mode – 3,2Hz


� Non-linear vulnerability analysis

� Pushover curve definition for lower and upper bounds

� Definition of performance objectives based on VISION 2000

Sismos

Frequentes(50% -30 anos)

43 anos

CompletamenteOperacional

OperacionalSalvaguarda de

vidaPróximo do

Colapso Níve

Níveis de Desempenho de Edifícios

mic

a

Sismos

0.75

0.9

Tr=475 (Raro)

Tr=975 (Muito Raro)

Tr=2475 (Máximo)

Capacidade inferior


Sismos Raros(10% -50 anos)

475 anos

Sismos Muito

Raros (5% -50 anos)

975 anos

OBJECTIVO BÀSICO

Níveis de desempenho de edifícios correntes

OBJECTIVO CRíTICO

Níveis de desempenho de instalações perigosasN

ive

is d

e I

nte

nsid

ade d

a A

cção

Sís

m

Sismos

Ocasionais(50% -50 anos)

72 anos

OBJECTIVO ESSENCIAL

Níveis de desempenho de edifícios essenciais

Sismo Máximo

(2% -50 anos)

2475 anos

0

0.15

0.3

0.45

0.6

0 2 4 6 8 10 12 14 16

Sa

(g)

Sd (cm)

Capacidade superior

Operacional - Início da endilhação

Salvaguarda de vida - Alteração de rigidez

Próximo do Colapso


General Conclusions

• The dynamic characterisation of large Civil Engineering structural systems constitutes a valuable tool for damage assessment


valuable tool for damage assessment

• Dynamic characterisation of structural systems can also be used also for vulnerability assessment (LS safety margins) of structural systems if complemented by:

▫ complementary information from destructive tests

▫ numerical modelling (able to reproduce the LS)


Case study #2:

Reinforced concrete substation



Adopted methodology

• Induced seismic intensity levels based on hazard curves and accumulated Arias intensities (I )


curves and accumulated Arias intensities (Ia)

• Definition of Limit States (LS) based on Damage Indexes (DI)

• Compare results thus obtained with performance objectives


PBEE - Methodology for

Experimental Assessment

• Induced seismic intensity levels based on hazard curves and accumulated Arias intensities (I )


curves and accumulated Arias intensities (Ia)

5.1

100,

1

,

,475

⋅=∑=

TESTa

n

i

TESTia

TESTnmI

I

yearsT

Test stage agm

[g] Tm

[years]

TEST25 0.10 68

TEST50 0.24 267

TEST100 0.47 728

TEST160 0.73 1416

TEST160_1 0.91 2004

TEST180 1.08 2573

5.1

1

⋅=

R

mgRgm

T

Taa




• Definition of Limit States (LS) based on Damage Indexes (DI)


Indexes (DI)

0

1f

fD n−=

Limit States (LS) Damage Index (D)

Damage Limitation (DL) 17%

Significant Damage (SD) 50%

Near Collapse (NC) 83%

DiPasquale




• Compare results obtained with

EC8-NA-zone 1.1-soil B

2,5

TR=68years

TR=267years

TR=728years

TR=1416years


obtained with performance objectives

▫ EC8

▫ IEC 60068-3-3

0

0,5

1

1,5

2

0,1 1 10 100

Frequency [Hz]

Acc

eler

atio

n n

orm

alis

ed f

or

equ

ipm

ent

[g]

TR=2004years

TR=2573years




100%

0 500 1000 1500 2000 2500 3000PUCBET

NORMAFIX base foundation bearingsPow er transformer base foundation bearings

• Compare results obtained with


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

68 267 728 1416 2004 2573

Seismic action return period [years]

Dam

age

ind

ex [

%]

Pow er transformer base foundation bearings

Damage Limitation (225 years)

Significant Damage (475 years)

Near Collapse (2475 years)

EFACEC electrical compliance tests

obtained with performance objectives

▫ EC8

▫ IEC 60068-3-3



Thank you for your attention!

experimental earthquake engineering research in lnec · seismic engineering research...

Documents