Title: Geotechnical Seismic Simulation
1Geotechnical Seismic Simulation
PEER 2002 Annual Meeting
Vision Professor Steven Kramer (PEER
Geotechnical Thrust Area Leader)
2Humboldt Bay, Middle Channel Bridge
Selected in Collaboration with Caltrans
Recently Pat Hipley Keith Porter (PEER) Cliff
Roblee Tom Shantz Mark Yashinsky
- 330 meters long, 9-span built in 1972 (seismic
retrofit in 95 00) - Supported on piles in soft soil vulnerable to
liquefaction - Near active seismic zone with reverse faulting
mechanism - Instrumented including nearby downhole array
3Project Goals
- Develop a bridge seismic assessment framework
based on computational modeling and sound
probabilistic analysis - Ultimately, a Decision Making Tool
- Estimate Maintenance/repair expenses
- Estimate down-time/reduced capacity
- Explore Retrofit scenarios
- Predict Emergency shutdown scenarios
4Maintenance/repair cost
5Down-time Lane closure.Emergency Shutdown
Professor Joel Conte
(e.g., repair cost or loss of functionality)
6OpenSees Professor Greg Fenves
Dr. Frank McKenna
Finite Element Model
Water Table
- Mesh generated using GID ( http//gid.cimne.upc.e
s - Prof. Pedro Arduino
- http//ce.washington.edu/geotech/opensees/)
Dr. Zhaohui Yang, Prof. Joel Conte
Abutments Structural Joints Liquefaction
SSI
7- Abutment Joints ZeroLength Element with
Gap-Hook Material -
Prof. Joel Conte
8Soil Constitutive Model
- Pressure-dependent multi-surface plasticity model
(for gravel, sand, and silt), incorporating
liquefaction effects -
Dr. Zhaohui Yang
9UC Berkeley Shear Tests Pestana, Seed, and
Kammerer
10SSI
Prof. Ross Boulanger
Comparison of Matlocks (1970) test on soft clay
and PySimple1 with the same loading path.
11Yang, Conte, Zhang
12Simulation of UC Davis Centrifuge Test
Kutter, Boulanger, Idriss, and Wilson
13Current Research Seismic Hazard Analysis
Dr. Paul Somerville
Site Specific Eq. motions at 3 Hazard Levels
(50, 10, and 2)
Middle Channel Bridge
J. Conte
14Current Research Spatial Definition of Input
Excitation
Lateral Boundaries, Base of the Mesh,
Transmitting boundary, Wave propagation
Plastic Bowl Method Prof. Jacobo Bielak/Prof.
Boris Jeremic
SCEC
153D 2D Mesh, Piles, and Abutments
4x3 pile model
Plastic zone
Professor Boris Jeremic
16OpenSees
100 years too late for this Bridge, But just
in time for Humboldt Bay.
UC Berkeley Photo Database