Quantification of variation in seismic response of bridges with

seat-type abutments to shear key modeling technique

PEER Transportation Systems Research Program Principal Investigator: Farzin Zareian, UC Irvine

Student Investigators: Bahareh Mobasher, UC Irvine, Peyman Kaviani,UC Irvine

University of California, Irvine

Objective Shear key Models

Conclusion • Deck Rotation in bridge is sensitive to employed exterior shear

key modeling technique and strength, and abutment skew

angle.

• Probability of shear key failure in the bridge with strut and tie

shear key model is smaller than sacrificial shear key model

for all skew angles

Evaluate effects of two

different exterior shear key

modeling techniques on

bridge response

Development of the sacrificial shear key

model using Concrete 02

Development of the shear key

model using bilinear material

based on Strut and Tie failure

mechanism

Record deck rotation and number of

shear key failures for each modeling

technique

Strut and Tie Shear Key Failure Strut and Tie failure

Test Observation of strut and Tie failure mechanism (Megally et

al.,2001. Bozorgzadeh et al. 2004)

Bridge Properties

Results

Concrete02

Model2(Sacrificial)

Concrete02

Angle μ(Strut and tie) σ(Strut and tie) μ(Sacrificial) σ(Sacrificial)

0 0.305 0.546 1.269 3.798

30 1.354 3.031 1.829 2.774

60 1.954 3.399 1.905 3.340

0

2

4

6

8 Bilinear Concrete02

0' 30' 60'

Skew Angle

Dec

k r

ota

tio

n (

Rad

.)

ENT

EPPG Bilinear

Bilinear

Model1(Strut and Tie)

0

200

400

600

800

1000

0 2 4 6

Displacement(in)

Forc

e(K

ips)

0 1 2 3 4 5 60

200

400

600

800

1000

Displacement(in)

Forc

e(K

ips)

Bridge A

Bridge Type Skewed

Length of Span 220.6ft

Number of Spans

2

Column Height 220ft

Column Type Single

Column

Abutment Type Seat Abut.

Sacrificial Strut and Tie

0 0.2 0.4 0.6 0.8 10

0.2

0.4

0.6

0.8

1

PGA(g)

Prob

abili

ty o

f she

ar k

ey fa

ilure

0' Strut and Tie

30' Strut and Tie

60' Strut and Tie

0' Sacrificial

30' Sacrificial

60' Sacrificial