随机地震作用下砂土液化概率分析

为了评价随机地震作用下饱和砂土孔隙水压力发展的概率,本文介绍了一种新的概率模型。模型中考虑了砂土动力特性的非线性、液化抗力的不确定性以及孔压发展的非线性,计算了每一荷载循环终了时的孔压累积概率分布函数,当孔压比等于1时,直接从累积概率分布函数中可得出液化概率。应用本方法,对日本新泻地震时的三个典型场地进行了分析,计算结果和现场震害良好一致,证实了本文方法的适用性。

Probabilistic Analysis of Sand Liquefaction under Stochastic Seismic Loading

A new probabilistic model is proposed to evaluate the development of pore pressure in saturated sands under random seismic loading. The nonlinear dynamic property of sands, the uncertainty of liquefaction resistance and the nonlinearity of development of pore pressure are considered in the model. The cumulative distribution functions of pore pressure at the end of any cycle of loading are computed. The probabilities of liquefaction are directly obtained from the functions when the pore pressuie ratio is 1.0. Three typical sites of Niigata Earthquake are analyzed with the new method. The good agreement of the calculated results with field observation confirms the applicability of this method.