两种一维土层地震反应分析方法对比

Comparative on two kinds of one-dimensional soil layer seismic response analysis methods

依托涵盖4类场地的72个真实土层钻孔剖面数据,对一维土层地震反应分析计算方法SHAKE91和DEEPSOIL进行系统对比,分析两种方法计算出的峰值加速度(PGA)和加速度反应谱(PSA)的异同,探讨其适用性。结果表明:两种方法计算得到的峰值加速度差异不仅随着场地变深软而增大,而且随着地震动输入强度(PRA)增大而增大;对于加速度反应谱的谱形,两种方法得到的结果具有相似性,均反映了场地的地震反应特点,但SHAKE91对加速度反应谱卓越周期的变化影响较大,而DEEPSOIL对输入地震动的高频成分保留更多;在场地条件较硬(I类)、输入地震动强度较弱(<0.1g)和输入地震动高频成分丰富(Nahanni波)时,SHAKE91和DEEPSOIL计算结果之间的差异可忽略不计。

Based on the data of 72 real soil layer drilling profiles covering 4 types of sites, a systematic comparison between the one-dimensional soil layer seismic response analysis and calculation methods SHAKE91 and DEEPSOIL was made, the similarities and differences between the peak ground acceleration(PGA) and peak spectral acceleration(PSA) calculated by the two methods were analyzed, and their applicability were discussed. The results showed that the difference of peak ground acceleration calculated by the two methods not only increased with the depth of the site, but also increased with the input intensity of ground motion. For the spectrum shape of peak spectral acceleration, the results obtained by the two methods were similar, which reflect the characteristics of seismic response of the site. However, SHAKE91 had a great influence on the change of predominant period of peak spectral acceleration, while DEEPSOIL retained more high-frequency components of input ground motion. When the site condition was hard(class I), the peak reflected acceleration(PRA) was weak(<0.1g) and the input ground motion high frequency component was rich(Nahanni wave), the difference between the calculated results of SHAKE91 and DEEPSOIL was ignored.