Seismic performance and design of bridge foundations in liquefiable ground with a frozen crust

Two major earthquakes in Alaska, namely 1964 Great Alaskan earthquake and 2002 Denali earthquake, occurred in winter season when the ground crust was frozen. None of the then-existing foundation types was able to withstand the force from the frozen crust overlying liquefied soils. This thesis aims to study how the frozen ground crust affects bridge pile foundation's performance and how to estimate the loads imposed on pile foundations. A shake table experiment was conducted to investigate the frozen ground crust – pile foundation interaction mechanism and collect data to validate a finite element (FE) model and a beam-on-nonlinear-Winkler-foundation (BNWF or p-y) model. The FE modeling was used to study the frozen ground crust impact on a selected bridge pile foundation. The p-y approach was used to predict the foundation performance. Guidelines were proposed for analyzing the seismic performance of pile foundations with the p-y approach for design practices in cold regions.