【摘要】 本文用直线上升、平台和下降等三段曲线组成的谱曲线近似表示实际加速度谱曲线,谱曲线下降指数γ设为随机变量。用该模型对700多条实际加速度谱曲线逐条进行拟合分析。将所得拟合谱的特征参数建立与震级、断层距、谱下降指数和场地平均剪切波速的地震动衰减统计关系。建议参考下降指数的累积概率分布选取γ值。结果可得到各类场地类别而且下降指数有明确累积概率水平的设计加速度谱表示式。更多还原

【Abstract】 In this paper,actual acceleration response spectral curve is approximated by the curve that is consisted of uplifted straight line,flat and descending curve. The descending indexes γ of fitting spectral curves are assumed to be stochastic variables. More than 700 actual acceleration spectral curves are simulated one by one with the model. The statistical relationship of ground motion attenuation between characteristic parameters of these fitting spectral curves and magnitude,fault distance,descending index of spectral curve,average shear wave velocity at sites can be established. The index γ is chosen according to the cumulative probability of index γ. Consequently the design acceleration spectra expression for various site types and for specific cumulative probability of γ index is derived.更多还原