Transcript NEESR-SG-2005 Seismic Simulation and Design of Bridge Columns under Combined Actions, and Implications on System Response University of Nevada, Reno University of Missouri, Rolla University of Illinois,

NEESR-SG-2005
Seismic Simulation and Design of
Bridge Columns under Combined
Actions, and Implications on System
Response
University of Nevada, Reno
University of Missouri, Rolla
University of Illinois, Champaign-Urbana
University of California, Los Angeles
Washington University, St. Louis
Participants
University of Nevada, Reno
David Sanders (Project PI)

University of Missouri,
Rolla
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Abdeldjelil “DJ” Belarbi (co-PI)
Pedro Silva
Ashraf Ayoub
University of IllinoisChampaign-Urbana
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Amr Elnashai (co-PI)
Reginald DesRoches (GaTech)

University of California,
Los Angeles
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Washington University, St.
Louis
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Jian Zhang (co-PI)
Shirley Dyke (co-PI)
University of Mexico
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Sergio Alcocer
Causes of Combined Actions
System to Component to System
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Functional Constraints - curved or skewed
bridges
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Geometric Considerations - uneven spans or
different column heights
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Multi-directional Earthquake Motions -
significant vertical motions input or near
field fling impacts
Structural Constraints - stiff deck,
movement joints, soil condition and
foundations
Significance of Vertical Motion

Effects of Vertical Motions on Structures
Direct Compressive Failure
 Reduction of Shear and Moment Capacity
 Increase in Shear and Moment Demand

Axial Force Response
Santa Monica Freeway, Pier 6
3100
2900
axial force: kN

2700
2500
2300
2100
1900
Transverse
Trans + Long
Trans + Vert
1700
1500
8
8.5
9
9.5
10
10.5
11
tim e: seconds
Significance of Torsion

Interaction of Shear-Torsion results in early cover
spalling of non-circular/rectangular cross-sections
due to circulatory shear stresses.
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What are the effects of warping on the flexural and
shear capacity of columns?

What is the impact of multiple loadings on thintube theory?

What are the effects on the curvature ductility and
location of the plastic hinge?
M-V-T Interactions
BendingShear
ShearTorsion
Combination of
Bending-ShearTorsion
Parameters
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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
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Type of Loading – Slow Cyclic, Pseudo-dynamic
and shake table/dynamic
Pre-test System Analysis
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Perform seismic simulations of bridge systems
under combined actions to study effects of various
bridge components on global and local seismic
response behavior of bridge system
 Bridge superstructure
 Columns (Piers)
 Foundations and surrounding soil
 Embankments
 Nonlinear soil-foundation-structure interaction
 Multi-directional motions
Analysis
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Selected 4 ground motion suites that incorporate the
site-dependent probabilistic hazard analysis and ground
motion disaggregation analysis.
Selected 2 bridge prototypes that are distinctive in
terms of structural characteristics and dynamic
properties.
Conducted time history analysis of prototype bridges
subjected to multi-directional ground shakings and
evaluate the effect of vertical motions on seismic
demand.
Implemented nonlinear structural and foundation
elements.
Examples of Prototype Bridges
Structural
Characteristics
Span/Span
Length
Design Example #4
Three-span continuous,
320 ft long
Two-column integral bent,
Pier Type
pinned at base
Abutment Type
Seat
Foundation
Spread Footing
Expansion
Expansion Bearings &
Joints
Shear Keys
Longitudinal: intermediate
bents & free movement at
abutments
Force Resisting
Mechanism
Transverse: intermediate
bent columns &
abutments
Design Example #8
Five-span continuous,
500 ft long
Two-column integral bent,
monolithic at top and base
Stub abutment/diaphragm
Pile
Expansion Bearings
Longitudinal: intermediate
bents and abutment backfill
Transverse: intermediate
bent columns and abutment
backfill
Structural Response of Bridge #8
Displacement Demand
Force Demand
time(s)
0.0E+00
-5.0E+02 0.0
5.0
10.0
15.0
20.0
-1.0E+03
-1.5E+03
-2.0E+03
-2.5E+03
time(s)
0.0E+00
0.0
5.0
10.0
15.0
-1.0E-02
Tension
1.0E-01
1.0E+02
5.0E+01
0.0E+00
-5.0E+01
0.0
5.0
10.0
20.0
-5.0E-03
Column in Bent#3
relative disp._x(ft)
shear force_x(kip)
5.0E-03
-1.5E-02
Bottom of Column in
1.5E+02
Bent#3
15.0
20.0
time(s)
-1.0E+02
5.0E-02
0.0E+00
0.0
5.0
10.0
15.0
-5.0E-02
20.0
time(s)
-1.5E+02
-1.0E-01
Top of Column in Bent#1
Column in Bent#1
8.0E+02
6.0E+02
8.0E-01
4.0E+02
2.0E+02
6.0E-01
0.0E+00
-2.0E+02 0.0
-4.0E+02
-6.0E+02
5.0
10.0
15.0
20.0
time(s)
-8.0E+02
Bottom of Column in Bent#1
relative disp._z(ft)
shear force_z(kip)
axial force(kip)
5.0E+02
axial relative disp.(ft)
1.0E+03
4.0E-01
2.0E-01
0.0E+00
-2.0E-01 0.0
5.0
10.0
15.0
-4.0E-01
20.0
time(s)
-6.0E-01
Column in Bent#1
1986 N. Palm Springs Earthquake
Pre-test Component Analysis
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Perform pretest simulations of test specimens
with realistic loading and boundary conditions
Provide guidance for tests conducted
 Optimize number and parameters of test specimens
 Identify realistic loading and boundary conditions
 Integrate various analytical models into the
framework of UI-Simcor for pseudo-dynamic hybrid
testing

Analytical Program
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Development Inelastic Models for RC Sections
under Combined Loading
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Modeling of Specimens tested under PseudoDynamic/Dynamic Conditions
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Complex and Simplified Tools
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Parametric Studies
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Bridge System Analysis
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Development of Seismic Design Criteria
Development Inelastic Models for RC
Sections under Combined Loading
Deficiencies of Available Analytical Models:
 Current Inelastic Frame software Packages
(e.g. OpenSees, Zeus-NL, FedeasLab) focus
on flexural behavior of RC members only.
 The combined axial/shear/flexural/torsional
behavior is not considered in current models.
Experimental Program
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Experimental investigation of columns under multidirectional loadings with varying levels of axial force
and axial-flexure interaction ratios linked to analysis.
Slow cyclic tests at UMR.
Pseudo-dynamic tests at UIUC
Dynamic tests at UNR
Integrated bridge test managed by UMR, tested at
UIUC
UMR Test Setup
Strong Wall Load Cell
Hydralic Jack
Load Stub
Hydraulic Actuators
Steel Strands
(Inside Column)
Test Unit
Support Blocks
Strong Floor
Test Setup
Strong Wall
Strong Wall
Loading Frame
Hydraulic Actuators
Load Stub
Test Unit
UMR Test 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
Rotation Angle –
Twist/Torsion

Test Unit Offset Angle
for Bi-Axial Bending
Loading
Frame
UMR Test Matrix
Shape
Ht.
Scale Design Directions
M01
- 24
108
1:2
High
U, A1
M02
M05
M06
M07
M08
M09
M10
M11
M12
M13
M14
-
108
108
150
150
150
150
150
150
150
150
108
1:2
1:2
1:2
1:2
1:2
1:2
1:2
1:2
1:2
1:2
1:2
High
High
High
Mod.
High
High
High
High
High
High
High
U, T, A1
U, T, A1
U, T, A1
U, A1
T, A2
U, T, A2
U (m)
U (M)
U, T (m)
U, T (M)
U
108
1:2
Mod.
U, T
156
1:2
Mod.
U, T
144
156
108
1:2
1:2
1:2
High
High
High
Earthquake
M15
M16
M17
24
24
24
24
24
24
-24x48
-24x48
- 24x48
- 24x48
- 24x24
- 24x24
- 24x24
- 24
- 24
- 24
Testing in June
Description
Level 1axial-high shearflexure(I01) (a)
M01 with torsion (e)
M02 with high torsion (c)
high torsion (d)
M01 with moderate details (b)
Level 2 axial-torsion (g)
Level 2 Axial (f)
Level 1 axial-low shear- (b)
M10 with bidirectional M (b)
M10 with torsion (d)
M11 with torsion (d)
Level 1 axial-high shear (a)
M14 with high torsion and
moderate details (c)
M15 with high torsion and
moderate details (d)
Prototype bridge evaluation –
DONE AT UIUC by UMR.
Column Fabrication
Column Testing
Specimen M07:
Ductility 8
Large Testing Facility, UIUC
Large Testing Facility, UIUC
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Three 6 DOF loading and boundary
condition boxes of capacity 3000kN
to 4500kN
Displacement capacity +/- 250 mm
per box
Reaction wall ~15x9x8 meters
Three advanced high speed DAC
systems
Video and J-Camera data capture
Simulation Coordinator UI-SIMCOR
for multi-site hybrid simulation
UIUI-SimCor
p.
Dis
Experiment
Module
r c.
Fo
Di
s
Fo
rc .
p.
Static Analysis
Module
Small Scale Testing Facility, UIUC
UIUC Experiment
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MISST test (previous multi-site test at UIUC) will provide the test bed
for the loading protocols
Tests of 3 large scale and 4 small scale bridge columns with different
aspect ratios and seismic design details using MUST-SIM Facility
Column test with UMR under different loading conditions
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Verify local and global analytical part of the hybrid simulation
Provide an opportunity for researchers outside of a NEES facility
Detailed design of UIUC and UNR experiments will be guided by bridge
system analysis
Test at UIUC
Small Scale Test
Large Scale Test
NEES-R
Test with UMR
Small-Scale Testing
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Current testing
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Several 1/16 scaled piers are currently being tested
Used to evaluate system and material/pier design
Test Setup
After Test
UNR Shake Table Facility
Previous 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 Program
Shape
N01
- 16
N02
- 16
N03
- 16
N04
- 16
N05
- 12x20
N06
N07
N08
Ht.
104
104
72
72
72
- 12x20
72
- 12x20
72
- 12x20
72
Scale
Design
1:3
High
1:3
High
1:3
High
1:3
High
1:4
High
1:4
High
1:4
High
1:4
High
Directions
CA,E1,E2
,T
VA,E1,E2
,T
CA,E1,E2
,T
VA,E1,E2
,T
Description
Constant axial, low
shear, torsion
N01 but with variable
axial load
Constant axial, high
shear, torsion
N03 but with variable
axial load
Variable axial, high
VA,E1,E2
shear
VA,E1,E2
N05 with torsion
,T
VA,E3,E4 N06 with near field
,T
motions
VA,E1,E2
N07 with high torsion
,T2
UMR Test at UIUC
UI-SIMCOR
Tested Structure
Structural Module
(Zeus-NL)
Soil & Foundation
Module
(OpenSees)
International Cooperation

University of Mexico
Shape
X01
- 20 x 20
Ht.
80
Scale
1:1.2
Design Directions
High
CA, U
X02
- 20 x 20
80
1:1.2
High
CA, U
X03
- 20x80
120
1:2
High
CA, U1
X04
- 20x80
120
1:2
High
CA, U2
Description
Strengthened prior
to testing
X01 with second
repair scheme
Bidirectional
Motion 1
Bidirectional
Motion 2
Educational Activities
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UCIST shake tables
incorporated for
hands-on exercises
and experiments
Existing K-12 outreach programs will be
enhanced with additional modules
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UNR: Summer camps and ME2L program
UIUC: Engineering Open House
UMR: High school engineering summer course
WU: GK-12 Program
Educational Activities
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Modules to be developed to enhance curriculum on
undergraduate and graduate levels
Undergraduates involved in research through REU
programs
Encourage students from underrepresented groups
through Minority Engineering Program, GAMES,
MERGE, and GetSet program
Online continuing education course to be developed at
UMR for practicing Engineers
UMR as NEES-POP
UMR
UMR as NEES-POP
UMR as NEES-POP
Questions??