Simulation and Performance of Bridge Abutments - 2552005

Project goals and objectives

The overall project goal is develop and validate numerical models in OPENSEES of bridge abutments over the next 2 years. We plan to utilize the results of ongoing Caltrans experiments on bridge abutments in the validation efforts. Specifically, the objectives in Year 9 are to:

1. Provide abutment structural details to Thrust Area Team for overall modeling effort.
2. Provide preliminary estimates of soil springs to Thrust Area Team for overall modeling effort, based on pseudo-static response. It is anticipated that improved dynamic springs would be periodically provided up through Year 10.
3. Participate in payload experiments with already planned Caltrans experiments on bridge abutments to be completed June 2006.
4. Collaborate on deep foundation and lateral spreading issues with PEER researchers.

Role of this project in supporting PEER's mission (vision)

This project supports PEER's vision by improving design methodologies for PBEE.

Methodology employed

The scope of this project is to provide the Thrust Area Team with input on bridge abutment modeling. This builds on current large-scale abutment experiments being carried out by the PI for Caltrans. This input will consist of structural details of abutments to improve the Team's modeling efforts, as well as input on geotechnical modeling and SFSI of the abutment system. In addition, the PI will continue to participate in the Thrust Area's efforts on liquefaction issues in regard to bridges.

A key component missing from PEER's OPENSEES bridge modeling efforts is proper modeling of the abutments. The ongoing abutment research being carried out by the PI presents a timely opportunity to efficiently provide this much needed input to PEER. The Phase 1 experiments focus on the translational pseudo-static soil springs behind the abutment as a function of soil type. These tests on 5.5-ft and 7.5-ft tall, 15-ft wide abutment backwalls in clayey sand and gravelly sand are to be completed in December 2005 and January 2006. These tests will be followed by an abutment system test, including pile and pile cap along with the back and wing walls in June 2006. Predictions of the pseudo-static response have already been made, and the details of the predictions including input parameters, will be provided to the Thrust Area Team. We will also collaborate with the team in order to provide necessary input for PEER's abutment modeling efforts. It is anticipated that an improved dynamic SFSI abutment model will be provided to PEER in Year 10.

Brief Description of previous year's achievements, with emphasis on accomplishments during last year (Year 8)

Last years achievements include completion of the analyses of the Tokachi full-scale lateral spreading experiments.

Other similar work being conducted within and outside PEER and how this project differs

This PEER project complements ongoing outside Caltrans research by implementing the results into OPENSEES bridge models, which would not be done otherwise. The PI is aware of some abutment testing to be carried out at UNR, and though quite similar to these experiments, will be carried out too late to use the results effectively within PEER.

Describe any instances where you are aware that your results have been used in industry

Results from the Tokachi blast experiments analyzed in Year 8 have been used in the design of port facilities on the west coast.

Expected milestones & deliverables

Milestones:

• - December 2005: Provide initial abutment information to Thrust Area Team.
• - February 2006: Complete Phase 1 Abutment Testing, provide refined static soil springs.
• - June 2006: Complete Phase 2 Abutment Testing.
• - September 2006: Provide updated soil springs.

Deliverables:

- PEER Quarterly Reports

Member company benefits

Improved soil design procedures for bridge abutments.