地震场地的综合评定方法

Nethod of Synthetic Assesment of Earthquake Site

本文给出了一个考虑场地土层的刚度、覆盖土层厚度及软弱夹层、液化土层等因素对场地地震动影响的综合评定方法。该方法根据场地土层的刚度和覆盖土层的厚度，按模糊评判方法确定场地指数μ值，并建立μ值与设计地震反应谱的关系。当场地指数确定时，就可确定用于抗震设计的反应谱。对于场地土层中含有软弱夹层或液化土层的情况，本文还给出了考虑这些影响因素，对场地指数或设计地震动参数进行修正的方法。

A method of synthetic assessment for earthquake site with considerations of the effects ofstiffness of site soil, depth of overlying soil, soft intettjedded layer and liquefaction layer is presented.Site index μ is firstiy detennined by synthetic assessment with fuzzy inference according to the stiffnessof site soil(the average shear modulus G)and depth of overlying soil(H_0). Value of μ is defined as thehasic index of measurement of the earthquake site effect. Relabonship betwen μ and the low frequencyturing period T_v, and hence the design earthquake rpectrum can be shown by the formula T_v=0. 65-0.45μ￣(0.4). Amending method with consideration of effects of soft interbedded layer and li-quefaction layer on site index and design earthquake response spectrum is aiso presented.