Simulation of 3-D Global Bridge Response to Shaking and Lateral Spreading

Scott J. Brandenberg, , Yili , and Minxing Zhao, UCLA

PEER Transportation Systems Research Program May 2, 2011 Project Description

PEER Transportation Systems Research Program 2/14 1-D site response analyses

• Ground Motion Records from 2007 Niigata Earthquake

• Records from Centrifuge Test

PEER Transportation Systems Research Program 3/14 1-D site response analyses

• Records from Numerical Simulation

10 with dilatancy ) 2 5

0

-5 Acceleration (m/s Acceleration Ground surface motion -10 0 10 20 30 Time (second)

1

0.5

0

-0.5

in loose sand -1 Excess Pore Pressure Ratio Pressure Pore Excess 0 10 20 30 Time (second)

10 ) 2 5

0

-5 Acceleration (m/s Acceleration Base input motion No.35 -10 0 10 20 30 Time (second) A liquefied sand layer is not a “base isolator”.

PEER Transportation Systems Research Program 4/14 1-D site response analyses

• Site Amplification Factor – Baseline Soil Profile

liq.liq. noliq.noliq. 10 10 ) ) 2 2 s / s / m m (

(

liq noliq a

1 a 1 S S

0.1 0.1 0.01 0.1 1 10 0.01 0.1 1 10 Period (second) Period (second) = Fa Sa liq/ Sa noliq a 1 1 a F Median of F of Median

median curve

0.1 0.01 0.1 1 10 0.01 0.1 1 10 Period (second) Period (second) PEER Transportation Systems Research Program 5/14 1-D site response analyses

• Site Amplification Factor – Monte Carlo Simulations a

F 1

f o

n a i d e M

0.01 0.1 1 10 Period (second)

PEER Transportation Systems Research Program 6/14 Modeling of the studied case

6 6

3 3 Disp (m) Disp (m) Disp(m) Disp (m) 0 1 2 0 1 2 -2 -1 0 -2 -1 0 0 0 0 0 7s Bridge and soil layer sketch Depth(m) 14s (m) Depth -3 -3 -3 21s -3 28s 35s -6 -6 (m) Depth

-6 Depth(m) 42s -6 49s 56s -9 -9 -9 63s -9 70s Soil layer simplification (a) Left abut (b) Left pier (c) Right pier (d) Right abut Longitudinal displacement profiles with motion No. 10

Bridge modeling

PEER Transportation Systems Research Program 7/14 Response plot

Longitudinal Transverse

PEER Transportation Systems Research Program 8/14 Response animation

PEER Transportation Systems Research Program 9/14 Optimal IM search

Data point 0.00674 Data point 0.04979 Transverse Transverse Longitudinal Longitudinal Square root Square root 0.01832 Regression Regression Square root 0.00248 Square root 0.00674

0.00248 9.11882E-4

9.11882E-4 Maximum pier column drift ratio pierdrift column Maximum Maximum pier column drift ratio columndrift Maximum pier

3.35463E-4 3.35463E-4 0.04979 0.13534 0.36788 1 2.71828 0.13534 0.36788 Longitudinal residual displacement (m) Longitudinal peak acceleration (g) Liquefaction case Non-liquefaction case

PEER Transportation Systems Research Program 10/14 CEDP =EDPLiq /EDPNon-Liq

• Goal: Provide estimate of CEDP as function of non-liquefied ground surface motion, structural properties, and soil properties.

Data Regression Cov=0.71 20.08554

7.38906 EDP C

2.71828 (EDP='Type 1' square-root column drift ratio) drift column square-root 1' (EDP='Type ∆

C 1 0.13534 0.36788 1 2.71828 7.38906 IM=Square-root CAD of IMnon-liquefaction motions (m)

PEER Transportation Systems Research Program 11/14 Local static analyses

• Numerical Model • Structural response ∆∆∆ top continuous superstructure

0 -2 -4 -6 ) m (

-8 h t

p -10 e

∆∆∆soil Icap D -12 Clay -14 Pile -16 Soil -18 Loose Sand 0 0.25 0.5 -8000 0 8000 -2000 0 2000 Lateral Displacement (m) Bending Moment (kN-m) Subgrade Reaction (kN/m)

Dense Sand

PEER Transportation Systems Research Program 12/14 Local static analyses

• Continuous Superstructure – Boundary conditions – Comparison of pile cap displacements

10 Prd 10

1 1 (m) ,top,1 ∆ cap,s C C

0.1 ∆ 0.1

0.01

0.001 0.01 0 5 10 15 20 0.01 0.1 1 10 ∆ Case No. cap,d (m)

PEER Transportation Systems Research Program 13/14 Questions?

Thank !

PEER Transportation Systems Research Program 14/14