【摘要】 饱和砂土地基在强震作用下会产生液化,导致其强度降低,并产生沉降、侧移和喷砂冒水等现象。基于YANG Zhao-hui提出的砂土液化本构模型,采用OpenSees对饱和砂土场地的地震反应进行了非线性动力有限元分析,阐述了液化机理以及对地基的作用;通过改变土性、地震动幅值、持时、频率等因素后数值模拟的对比,分析了各因素对可液化场地地震反应的影响。结果表明,饱和松砂场地更易产生液化;大震下场地更易产生液化;长持时的地震动更易造成液化;高频和低频的地震动均不易造成液化,而存在一个最易造成液化的中间频率值。更多还原

【Abstract】 Saturated sand foundation will be liquefied under strong earthquakes,leading to strength decrease,with phenomena such as settlement,lateral slippage and wet sand blasting.Based on constitutive model for sand liquefaction proposed by YANG Zhao-hui,nonlinear dynamic finite element analysis of seismic responses of saturated sand site was executed by use of OpenSees;mechanism of liquefaction and effect on foundation were expounded.Furthermore,after changing soil property and amplitude,duration,frequency of earthquake,the results of numerical simulation were compared;influence of these factors on seismic responses of liquefiable site was analyzed.The results show that:saturated loose sand site is more likely to be liquefied;site is more likely to be liquefied under stronger earthquakes;long-duration earthquakes are more likely to cause liquefaction;high-frequency earthquakes and low-frequency earthquakes are both not likely to cause liquefaction,and an intermediate frequency most likely to cause liquefaction exists.更多还原