Our own Ben Turner (future Dr. Turner!) was lead author on a report by the Pacific Earthquake Engineering Research Center (PEER) on liquefaction and lateral spreading effects on bridges. The report is titled “Evaluation of Collapse and Non-Collapse of Parallel Bridges Affected by Liquefaction and Lateral Spreading”. Ben’s coauthors are Dr. Scott J. Brandenberg and Dr. Jonathan P. Stewart of the Department of Civil and Environmental Engineering at UCLA. From the abstract:
The Pacific Earthquake Engineering Research Center and the California Department of Transportation have recently developed design guidelines for computing foundation demands during lateral spreading using equivalent static analysis (ESA) procedures. In this study, ESA procedures are applied to two parallel bridges that were damaged during the 2010 M 7.2 El Mayor-Cucapah earthquake in Baja California, Mexico. The bridges are both located approximately 15 km from the surface rupture of the fault on soft alluvial soil site conditions. Estimated median ground motions in the area in the absence of liquefaction triggering are peak ground accelerations = 0.27g and peak ground velocity = 38 cm/sec (RotD50 components). The bridges are structurally similar and both are supported on deep foundations, yet they performed differently during the earthquake. A span of the pile-supported railroad bridge collapsed, whereas the drilled-shaft-supported highway bridge suffered only moderate damage and remained in service following the earthquake. The ESA procedures applied to the structures using a consistent and repeatable framework for developing input parameters captured both the collapse of the railroad bridge and the performance of the highway bridge. Discussion is provided on selection of the geotechnical and structural modeling parameters as well as combining inertial demands with kinematic demands from lateral spreading.
This report is part of Ben’s work on his doctoral dissertation. You can download the report by clicking on the linked citation below.