Pushover analysis for the lateral pile subjected to liquefaction-induced flow earth pressure

This paper presents a simplified nonlinear pushover analysis for the lateral response of the pile subjected to liquefaction-induced flow earth pressure. The pushover analysis can be carried out by incrementally imposing flow pressure or flow displacement on the nonlinear pile. The capacity curve of the lateral pile was expressed in terms of the total flow force and the displacement of pile top, thus, seismic performances corresponding to different liquefaction extents can be clearly identified on the curve. Using SAP2000 software, the non-linear pile was modeled by a tri-linear moment-curvature relationship and the soil-pile interaction was simulated by an elastic-perfectly plastic spring. On well-documented field damage case was analyzed by both the flow pressure and displacement methods and comparisons were made between the results of these two methods. It shows that both two methods can reasonably capture the lateral pile response when subjected the flow pressure due to ground liquefaction, however, the flow pressure method seems more suitable to be used in the area of seismic performance-based design of pile foundation.