NEESR-SG-2005NEESR-SG-2005SeismicSeismic Simulation and Simulation and

Design of Bridge Columns Design of Bridge Columns under Combined Actions, and under Combined Actions, and

Implications on System Implications on System ResponseResponseUniversity of Nevada, Reno

University of Missouri, RollaUniversity of Illinois, Champaign-Urbana

University of California, Los AngelesWashington University, St. Louis

ParticipantsParticipants

University of Nevada, RenoUniversity of Nevada, RenoDavid Sanders (Project PI)David Sanders (Project PI)

University of Missouri, University of Missouri, RollaRolla Abdeldjelil “DJ” Belarbi (co-PI)Abdeldjelil “DJ” Belarbi (co-PI) Pedro SilvaPedro Silva Ashraf AyoubAshraf Ayoub

University of Illinois-University of Illinois-Champaign-UrbanaChampaign-Urbana Amr Elnashai (co-PI)Amr Elnashai (co-PI) Reginald DesRoches (GaTech)Reginald DesRoches (GaTech)

University of University of California, Los California, Los AngelesAngeles Jian Zhang (co-PI)Jian Zhang (co-PI)

Washington Washington University, St. LouisUniversity, St. Louis Shirley Dyke (co-PI)Shirley Dyke (co-PI)

University of Mexico University of Mexico Sergio AlcocerSergio Alcocer

Causes of Combined Causes of Combined ActionsActions

System to Component to SystemSystem to Component to System Functional Constraints Functional Constraints - curved or - curved or

skewed bridges skewed bridges Geometric Considerations - Geometric Considerations - uneven uneven

spans or different column heightsspans or different column heights Multi-directional Earthquake Multi-directional Earthquake

Motions Motions -significant vertical motions -significant vertical motions input or near field fling impactsinput or near field fling impacts

Structural Constraints Structural Constraints - stiff deck, - stiff deck, movement joints, soil condition and movement joints, soil condition and foundationsfoundations

Significance of Vertical Significance of Vertical Motion Motion Effects of Vertical Motions on StructuresEffects of Vertical Motions on Structures

Direct Compressive FailureDirect Compressive Failure Reduction of Shear and Moment CapacityReduction of Shear and Moment Capacity Increase in Shear and Moment DemandIncrease in Shear and Moment Demand

Axial Force ResponseAxial Force Response

Santa Monica Freeway, Pier 6

1500

1700

1900

2100

2300

2500

2700

2900

3100

8 8.5 9 9.5 10 10.5 11

time: seconds

axia

l fo

rce:

kN

TransverseTrans + LongTrans + Vert

Significance of Torsion Interaction of Shear-Torsion results in

early cover spalling of non-circular/rectangular cross-sections due to circulatory shear stresses.

What are the effects of warping on the flexural and shear capacity of columns?

What is the impact of multiple loadings on thin-tube theory?

What are the effects on the curvature

ductility and location of the plastic hinge?

Bending-Shear

Shear-

Torsion

Combination of Bending-Shear-Torsion

M-V-T Interactions

ParametersParameters Cross-section - Circle, Interlocking Spiral, Square Column aspect ratio - moment/shear ratio Torsion/shear ratio - high and low torsion Level of axial loads Level of detailing for high and moderate seismicity Bidirectional bending moment - non-circular

cross-sections Type of Loading – Slow Cyclic, Pseudo-dynamic and

shake table/dynamic

Pre-test System AnalysisPre-test System Analysis Perform seismic simulations of bridge Perform seismic simulations of bridge

systems under combined actions to study systems under combined actions to study effects of various bridge components on effects of various bridge components on global and local seismic response behavior of global and local seismic response behavior of bridge systembridge system Bridge superstructureBridge superstructure Columns (Piers)Columns (Piers) Foundations and surrounding soilFoundations and surrounding soil EmbankmentsEmbankments Nonlinear soil-foundation-structure interactionNonlinear soil-foundation-structure interaction Multi-directional motionsMulti-directional motions

Analysis Analysis Selected 4 ground motion suites that incorporate Selected 4 ground motion suites that incorporate

the site-dependent probabilistic hazard analysis the site-dependent probabilistic hazard analysis and ground motion disaggregation analysis.and ground motion disaggregation analysis.

Selected 2 bridge prototypes that are distinctive Selected 2 bridge prototypes that are distinctive in terms of structural characteristics and in terms of structural characteristics and dynamic properties.dynamic properties.

Conducted time history analysis of prototype Conducted time history analysis of prototype bridges subjected to multi-directional ground bridges subjected to multi-directional ground shakings and evaluate the effect of vertical shakings and evaluate the effect of vertical motions on seismic demand.motions on seismic demand.

Implemented nonlinear structural and Implemented nonlinear structural and foundation elements.foundation elements.

Examples of Prototype Examples of Prototype BridgesBridges

Structural Structural CharacterisCharacteris

ticstics

Design Example Design Example #4#4 Design Example #8Design Example #8

Span/Span Span/Span LengthLength

Three-span Three-span continuous, 320 ft continuous, 320 ft

longlong

Five-span continuous,Five-span continuous,

500 ft long500 ft long

Pier TypePier TypeTwo-column Two-column

integral bent, integral bent, pinned at basepinned at base

Two-column integral Two-column integral bent, monolithic at bent, monolithic at

top and basetop and baseAbutment Abutment

TypeType SeatSeat Stub Stub abutment/diaphragmabutment/diaphragm

FoundationFoundation Spread FootingSpread Footing PilePileExpansion Expansion

JointsJointsExpansion Bearings Expansion Bearings

& Shear Keys& Shear Keys Expansion Bearings Expansion Bearings

Force Force Resisting Resisting

MechanismMechanism

Longitudinal: Longitudinal: intermediate bents intermediate bents & free movement at & free movement at

abutmentsabutments

Transverse: Transverse: intermediate bent intermediate bent

columns & columns & abutmentsabutments

Longitudinal: Longitudinal: intermediate bents intermediate bents

and abutment backfilland abutment backfill

Transverse: Transverse: intermediate bent intermediate bent

columns and columns and abutment backfillabutment backfill

-1.0E-01

-5.0E-02

0.0E+00

5.0E-02

1.0E-01

0.0 5.0 10.0 15.0 20.0

time(s)

rela

tive

dis

p._

x(ft

)

-6.0E-01

-4.0E-01

-2.0E-01

0.0E+00

2.0E-01

4.0E-01

6.0E-01

8.0E-01

0.0 5.0 10.0 15.0 20.0

time(s)

rela

tive

dis

p._

z(ft

)

Column in Bent#3

Column in Bent#1

Column in Bent#1

Displacement Demand

-1.5E-02

-1.0E-02

-5.0E-03

0.0E+00

5.0E-03

0.0 5.0 10.0 15.0 20.0

time(s)

axia

l re

lati

ve d

isp

.(ft

)

Tension

Bottom of Column in Bent#1

Structural Response of Structural Response of Bridge #8Bridge #8

Structural Response of Structural Response of Bridge #8Bridge #8

-2.5E+03

-2.0E+03

-1.5E+03

-1.0E+03

-5.0E+02

0.0E+00

5.0E+02

1.0E+03

0.0 5.0 10.0 15.0 20.0

time(s)

axia

l fo

rce(

kip

)

-1.5E+02

-1.0E+02

-5.0E+01

0.0E+00

5.0E+01

1.0E+02

1.5E+02

0.0 5.0 10.0 15.0 20.0

time(s)

shea

r fo

rce_

x(ki

p)

-8.0E+02

-6.0E+02

-4.0E+02

-2.0E+02

0.0E+00

2.0E+02

4.0E+02

6.0E+02

8.0E+02

0.0 5.0 10.0 15.0 20.0

time(s)

shea

r fo

rce_

z(ki

p)

Bottom of Column in Bent#3

Top of Column in Bent#1

Force Demand

1986 N. Palm Springs Earthquake

Pre-test Component AnalysisPre-test Component Analysis Perform pretest simulations of test Perform pretest simulations of test

specimens with realistic loading and specimens with realistic loading and boundary conditionsboundary conditions Provide guidance for tests conductedProvide guidance for tests conducted Optimize number and parameters of test Optimize number and parameters of test

specimensspecimens Identify realistic loading and boundary Identify realistic loading and boundary

conditionsconditions Integrate various analytical models into the Integrate various analytical models into the

framework of UI-Simcor for pseudo-dynamic framework of UI-Simcor for pseudo-dynamic hybrid testinghybrid testing

Analytical ProgramAnalytical Program Development Inelastic Models for RC Sections Development Inelastic Models for RC Sections

under Combined Loadingunder Combined Loading

Modeling of Specimens tested under Pseudo-Modeling of Specimens tested under Pseudo-Dynamic/Dynamic ConditionsDynamic/Dynamic Conditions Complex and Simplified ToolsComplex and Simplified Tools

Parametric StudiesParametric Studies

Bridge System AnalysisBridge System Analysis

Development of Seismic Design CriteriaDevelopment of Seismic Design Criteria

Development Inelastic Models for RC Development Inelastic Models for RC Sections under Combined LoadingSections under Combined Loading

Deficiencies of Available Analytical Deficiencies of Available Analytical Models:Models:

Current Inelastic Frame software Current Inelastic Frame software Packages (e.g. OpenSees, Zeus-Packages (e.g. OpenSees, Zeus-NL, FedeasLab) focus on flexural NL, FedeasLab) focus on flexural behavior of RC members only.behavior of RC members only.

The combined The combined axial/shear/flexural/torsional axial/shear/flexural/torsional behavior is not considered in behavior is not considered in current models.current models.

Experimental ProgramExperimental Program

Experimental investigation of columns Experimental investigation of columns under multi-directional loadings with under multi-directional loadings with varying levels of axial force and axial-varying levels of axial force and axial-flexure interaction ratios linked to flexure interaction ratios linked to analysis.analysis.

Slow cyclic tests at UMR.Slow cyclic tests at UMR. Pseudo-dynamic tests at UIUC Pseudo-dynamic tests at UIUC Dynamic tests at UNRDynamic tests at UNR Integrated bridge test managed by Integrated bridge test managed by

UMR, tested at UIUCUMR, tested at UIUC

UMR Test SetupUMR Test Setup

Test SetupTest Setup

Position of (2) Horizontal Actuators. Actuators Position for S-Pattern loading

Test Unit (Interlocking Spiral Column Setup for Bi-Axial Bending Shown)

Loading Frame

Loading Frame Rotation Angle – Twist/Torsion

Test Unit Offset Angle for Bi-Axial Bending

UMR Test SetupUMR Test Setup

Shape Ht. Scale Design Directions Description

M01 - 24 108 1:2 High U, A1 Level 1axial-high shear-flexure(I01) (a)

M02 - 24 108 1:2 High U, T, A1 M01 with torsion (e) M05 - 24 108 1:2 High U, T, A1 M02 with high torsion (c) M06 - 24 150 1:2 High U, T, A1 high torsion (d) M07 - 24 150 1:2 Mod. U, A1 M01 with moderate details (b) M08 - 24 150 1:2 High T, A2 Level 2 axial-torsion (g) M09 - 24 150 1:2 High U, T, A2 Level 2 Axial (f) M10 -24x48 150 1:2 High U (m) Level 1 axial-low shear- (b) M11 -24x48 150 1:2 High U (M) M10 with bidirectional M (b) M12 - 24x48 150 1:2 High U, T (m) M10 with torsion (d) M13 - 24x48 150 1:2 High U, T (M) M11 with torsion (d) M14 - 24x24 108 1:2 High U Level 1 axial-high shear (a)

M15 - 24x24

108 1:2 Mod. U, T M14 with high torsion and moderate details (c)

M16 - 24x24

156 1:2 Mod. U, T M15 with high torsion and moderate details (d)

M17 - 24 - 24 - 24

144 156 108

1:2 1:2 1:2

High High High

Earthquake Prototype bridge evaluation – DONE AT UIUC by UMR.

Testing in June

UMR Test MatrixUMR Test Matrix

Column FabricationColumn Fabrication

Column TestingColumn Testing

Specimen Specimen M07: M07:

Ductility 8Ductility 8

Large Testing Facility, Large Testing Facility, UIUCUIUC

Large Testing Facility, Large Testing Facility, UIUCUIUC

Experiment Module

Static Analysis Module

UIUI--SimCorSimCor

Disp.Disp.

Forc.Forc.

Experiment Module

Static Analysis Module

UIUI--SimCorSimCor

Disp.Disp.

Forc.Forc.

Three 6 DOF loading and Three 6 DOF loading and boundary condition boxes of boundary condition boxes of capacity 3000kN to 4500kNcapacity 3000kN to 4500kN

Displacement capacity +/- Displacement capacity +/- 250 mm per box250 mm per box

Reaction wall ~15x9x8 Reaction wall ~15x9x8 metersmeters

Three advanced high speed Three advanced high speed DAC systemsDAC systems

Video and J-Camera data Video and J-Camera data capturecapture

Simulation Coordinator UI-Simulation Coordinator UI-SIMCOR for multi-site SIMCOR for multi-site hybrid simulationhybrid simulation

Small Scale Testing Small Scale Testing Facility, UIUCFacility, UIUC

UIUC ExperimentUIUC Experiment MISST test (previous multi-site test at UIUC) will provide MISST test (previous multi-site test at UIUC) will provide

the test bed for the loading protocolsthe test bed for the loading protocols Tests of 3 large scale and 4 small scale bridge columns Tests of 3 large scale and 4 small scale bridge columns

with different aspect ratios and seismic design details with different aspect ratios and seismic design details using MUST-SIM Facilityusing MUST-SIM Facility

Column test with UMR under different loading conditionsColumn test with UMR under different loading conditions Verify local and global analytical part of the hybrid simulationVerify local and global analytical part of the hybrid simulation Provide an opportunity for researchers outside of a NEES Provide an opportunity for researchers outside of a NEES

facilityfacility Detailed design of UIUC and UNR experiments will be guided Detailed design of UIUC and UNR experiments will be guided

by bridge system analysisby bridge system analysis

Test at UIUC

Small Scale Test Large Scale Test Test with UMR

NEES-R

Small-Scale TestingSmall-Scale Testing Current testing Current testing

Several 1/16 scaled piers are currently being testedSeveral 1/16 scaled piers are currently being tested Used to evaluate system and material/pier designUsed to evaluate system and material/pier design

Test Setup After Test

UNR Shake Table FacilityUNR Shake Table FacilityPrevious Tests have Focused on Unidirectional Motion.

System of Decoupling the Vertical Load and Inertial Mass has been used.

Vertical Load was Held Constant.

A system will now be used to decouple variable axial load from the inertial load with bi-directional lateral shaking.

UNR ProgramUNR Program Shape Ht. Scale Design Directions Description

N01 - 16 104

1:3 High CA,E1,E2,T

Constant axial, low shear, torsion

N02 - 16 104

1:3 High VA,E1,E2,T

N01 but with variable axial load

N03 - 16 72

1:3 High CA,E1,E2,T

Constant axial, high shear, torsion

N04 - 16 72

1:3 High VA,E1,E2,T

N03 but with variable axial load

N05 - 12x20 72

1:4 High VA,E1,E2 Variable axial, high shear

N06 - 12x20 72

1:4 High VA,E1,E2,T

N05 with torsion

N07 - 12x20 72

1:4 High VA,E3,E4,T

N06 with near field motions

N08 - 12x20 72

1:4 High VA,E1,E2,T2

N07 with high torsion

Tested Structure

Soil & Foundation

Module

(OpenSees)

UI-UI-SIMCORSIMCOR

Disp.Disp.

ForceForce

Structural Module

(Zeus-NL)

UMR Test at UIUCUMR Test at UIUC

International CooperationInternational Cooperation

University of MexicoUniversity of Mexico Shape Ht. Scale Design Directions Description X01 - 20 x 20 80 1:1.2 High CA, U Strengthened prior

to testing X02 - 20 x 20 80 1:1.2 High CA, U X01 with second

repair scheme X03 - 20x80 120 1:2 High CA, U1 Bidirectional

Motion 1 X04 - 20x80 120 1:2 High CA, U2 Bidirectional

Motion 2

Educational ActivitiesEducational Activities UCIST shake UCIST shake

tables tables incorporated for incorporated for hands-on hands-on exercises and exercises and experimentsexperiments

Existing K-12 outreach programs will Existing K-12 outreach programs will be enhanced with additional modulesbe enhanced with additional modules UNR: Summer camps and ME2L programUNR: Summer camps and ME2L program UIUC: Engineering Open HouseUIUC: Engineering Open House UMR: High school engineering summer UMR: High school engineering summer

coursecourse WU: GK-12 ProgramWU: GK-12 Program

Educational ActivitiesEducational Activities

Modules to be developed to enhance Modules to be developed to enhance curriculum on undergraduate and graduate curriculum on undergraduate and graduate levelslevels

Undergraduates involved in research through Undergraduates involved in research through REU programsREU programs

Encourage students from underrepresented Encourage students from underrepresented groups through Minority Engineering groups through Minority Engineering Program, GAMES, MERGE, and GetSet Program, GAMES, MERGE, and GetSet programprogram

Online continuing education course to be Online continuing education course to be developed at UMR for practicing Engineersdeveloped at UMR for practicing Engineers

UMR as NEES-POPUMR as NEES-POP

UMRUMR

UMR as NEES-POPUMR as NEES-POP

UMR as NEES-POPUMR as NEES-POP

Questions??Questions??