Soil-structure interaction analysis of lateral resistance of piles in liquefied and laterally spreading ground

In this paper, the lateral resistance of piles subject to the actions of liquefaction-induced lateral spreading of the ground was investigated. The Winkler foundation model was utilized for the modeling of pile-soil interaction. The soil springs with nonlinear p-y curves were used to describe the relationship of soil reaction versus lateral displacement around the pile. The distributed plastic hinges were deployed to simulate the possible flexural failure of the pile. The actions due to lateral spreading of liquified ground were modeled as flow displacement and flow pressure, respectively. For the former, the free-field ground displacement profile is assigned to the pile-soil system; while the latter imposes the liquefaction-induced flow pressure directly on the pile. One of the pile failure cases due to lateral spreading of liquified ground in the 1995 Kobe Earthquake was adopted for case study. The obtained pile damage states from flow displacement and flow pressure methods were compared with the field observations, and the validity and feasibility of both methods were accordingly examined.