近场速度脉冲场地响应等效线性分析的适用条件

摘要

为了探讨近场强地震动中产生较大永久位移的"单向"速度大脉冲和近似不产生永久位移的"双向"速度大脉冲是否可用等效线性化方法分析处理,选取具有典型特性的地震动作为输入,通过"方法自检验"和"前人成果定性比较"等手段 ,分析了近场速度脉冲场地响应采用等效线性方法进行分析的适用条件. 计算结果表明:对于"弱"和"中等"强度的近场"双向"速度脉冲型地震动作用,可以采用等效线性化方法进行分析. 这种做法是合理的、有效的. 但是,对于近场"单向"速度大脉冲型地震动作用,不适宜采用等效线性化方法进行分析,计算结果将会产生很大误差,尤其是不能反映场地永久位移和永久塑性变形特征.%In order to explore the feasibility of equivalent linearization method, this paper takes the near-field strong ground motion with typical characteristics, specifically, one-way large velocity pulses with a large permanent dis-placement, and two-way large velocity pulses with no permanent displacement, as input, the applicable conditions of using equivalent linearization method to analyze the near-field site response of large velocity pulse are calculated and analyzed by self-examination method and qualitative comparison method of previous results.The results show that:for the weak and moderate two-way large velocity pulse-type near-field ground motions, the equivalent linear-ization method is reasonable and effective.However, the equivalent linearization method is not appropriate for one-way large velocity pulse-type near-field ground motion, the calculation result will have large error.In particular, it does not reflect permanent displacement and plastic deformation characteristics of site.