Project:  Effects of Long-Duration, Long-Period Ground Motions on Bridge Foundation System Performance

PI(s):  Pedro Arduino

Sponsor:  PEER-NSF

Objective:   Reliable prediction of the performance of bridge systems requires an accurate understanding of the behavior of the superstructure and foundation systems, and of the interaction of these last elements with the surrounding soil. One problem in particular that requires further research is the analysis of the response of bridge foundation systems subjected to long-duration, long-period earthquake excitations.

In this context, the objectives of this research project are: (1) to evaluate the performance of typical bridge foundation systems subjected to long-period, long-duration ground motions by means of advanced numerical models and (2) to compare that performance with the performance due to ground motions consistent with current design requirements.

Research Approach: To accomplish the research objectives several tasks have been considered:

a) Identification of typical bridge foundations systems commonly used by WSDOT and CALTRANS.

b) Development of site specific soil profiles and generic soil profiles for the states of Washington, and California.

c) Generation of synthetic motions for subduction zone events in order to develop site-specific input ground motions.

d) Identification and/or development of advanced numerical models capable of modeling the foundation system, soil conditions, and loading characteristics.

e) Evaluation of the suggested numerical tool.

To date, several pile foundation systems have been analyzed by means of DYNAPILE. For that purpose, specific P-Y curves have been developed for each site, and different motions have been considered. Location and maximum values of displacement, bending moment, and shear stresses are determined for each configuration. A matlab function that allows for the visualization of the pile performance during the excitation has been created.

For more information send E-Mail to: parduino@u.washington.edu