【摘要】 工程上常用的等效线性化方法在处理常见的、含厚软表层的海域场地时,其计算结果往往产生较大的偏异.为了研究这些计算偏异产生的程度,本文利用等效线性化方法对典型海域工程钻孔进行了小震、中震和大震3种不同工况下保留和舍弃软表层情况下的土层计算.考虑到在大震作用下,土体可能进入大的非线性范围,等效线性化将不再适用,故引入了一种能更好地考虑土层大非线性效应的直接时域积分方法,并与等效线性化方法研究结果进行了对比分析.在此基础上,给出了确定含厚软表层海域工程场地设计地震动参数的处理建议.更多还原

【Abstract】 Nowadays, equivalent linearization method is widely used, but the computed result always has great deviation while dealing with common offshore engineering sites with deep soft surface layers. In order to show the extent of the deviation, we choose a typical borehole and use equivalent linearization method to analyze the site responses under the excitation of minor, moderate and major ground motions. In this procedure, borehole models with or without soft surface layers are considered. As we known, soil has large variation range of nonlinear behaviour under severe earthquakes and equivalent linearization method can not fit well, so a direct time-domain integral method is introduced and compared with equivalent linearization method. Based on the above analysis, some solutions to the determination of design ground motion for offshore engineering sites with deep soft surface layers are proposed and discussed.更多还原