一维等效线性化土层地震反应分析程序的代表有 LSSRLI-1与 SHAKE2000。LSSRLI-1是我国地震安评工作中推荐使用的程序,代表20世纪80年代的国际先进水平,而目前代表国际先进水平是 SHAKE2000。针对等效线性化程序存在的不足,有必要对 LSSRLI-1进行改进。为了寻找 LSSRLI-1与 SHAKE2000之间的差异,通过建立Ⅰ至Ⅳ类场地的土层剖面模型,对比分析两程序的计算结果,得到在不同场地条件下两程序的差异情况以及这些差异的变化规律。结果表明,Ⅰ、Ⅱ类场地中两程序计算结果差异不大,Ⅲ、Ⅳ类场地中两程序计算的 PGA、反应谱与剪应变结果差异较大。初步分析可知,剪应变相对差与 PGA、反应谱、剪切模量相对差存在相关性,通过修正剪应变的计算可以缩小 LSSRLI-1结果与 SHAKE2000结果的差距。%The one-dimensional equivalent linear method for soil layer seismic response analysis is widely used in engineering practices and academic fields.LSSRLI-1 and SHAKE2 000 are typical codes.LSSRLI-1,which represents the 1 980s skill level,is recommended in Chinese manuals on seismic safety evaluation practices.SHAKE2 000 represents a more internationally advanced level. Improvements to LSSRLI-1 must be made with respect to the drawbacks of the equivalent linear method it uses.To reveal the differences between LSSRLI-1 and SHAKE2000,we established a horizontal layered model for class-Ⅰ to class-Ⅳ sites.Then we ran the two programs on the same working cases.A comparison and statistical analysis of the results shows the difference between the two programs and we therefore propose a variation of the relative deviation rule.Results indi-cate that peak ground acceleration (PGA),the spectrum,and the shear strain results do not obvi-ously coincide in class-Ⅲ and class-Ⅳ site conditions.But in class-Ⅰ and class-Ⅱ sites condi-tions,there is little difference between the results of the two programs.After preliminary analy-sis,we conclude that the shear strain calculation method can be improved by modifying the shear modulus method to narrow the gap between LSSRLI-1 and SHAKE2000 results.We make this conclusion on the basis of the relative relationships between the shear strain,the PGA,the spec-trum,and the shear modulus relative deviation.
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