Warming effects on permafrost under earthquake motions and seismic stability of pile foundation of dry bridge

摘要

A series of shaking table tests for the 1 : 100 scaled model of the pile foundation in the Qingshuinriver Bridge along the Qinghai–Tibet Railroad were conducted on condition that the soilntemperature around pile was below 0uC. The change of temperature around the pile foundationnduring the earthquake motions was monitored, and the warming effects on the permafrost werenobtained. Applying dynamic finite element analysis method, the characteristics of seismicnresponse of the pile foundation were analysed. In the dynamic time history analysis, the artificialnseismic waves were used as the input ground motions. The effects of the peak acceleration andnfrequency characteristic of input ground motions on seismic stability of the pile foundation ofnbridges at the unstable permafrost areas of high temperature and high ice content werendetermined. The distributions of dynamic displacement, acceleration and earth pressure werenstudied and the dynamic stability of the pile foundation of bridges was evaluated.