【摘要】 在地震荷载作用下，由于土体振动孔隙水压力的产生，桩的竖向承载力将发生退化。基于桩的竖向承载机理以及地震作用下土的有效应力状态变化，提出了桩竖向抗震承载力退化效应的有效应力动力分析方法，分别建立了地震作用下极限桩侧阻力和极限桩端阻力的退化计算模型。最后应用该方法对液化砂土地基上的桩基进行了竖向抗震承载力退化计算。更多还原

【Abstract】  When subjected to seismic loading pile vertical capacity undergoes significant degradation due to the buildup of pore－water pressure． On the basis of the mechanism of pile vertical capacity and the changes of effective stress state of soil an effective stress analysis method was presented in this paper which is capable of describing the vertical capacity behavior of pile during such an event． Two degradation models are respectively proposed for modeling ultimate shaft resistance and tip resistance of pile during earthquakes． Finally the proposed numerical method is applied to the calculation of the degradation for vertical seismic capacity of a pile foundation on liquefied sand．更多还原