【摘要】 在研究西安地区大量钻孔资料的基础上,构造了44个不同等效剪切波速和覆盖层厚度场地条件下的典型场地剖面,利用一维等效线性化地震反应分析方法,计算了不同场地在3种不同强度的地震动输入下的地面峰值加速度,分析了地震动峰值加速度放大系数ks随场地类别、等效剪切波速Vse、覆盖层厚度H和输入地震动强度ar的变化特征,指出了按场地类别对地震动峰值加速度调整存在的问题。分析结果表明,加速度放大系数随等效剪切波速、覆盖层厚度及基岩输入地震动强度的增大而减小;等效剪切波速对加速度放大系数的影响大于覆盖层厚度的影响,随着输入地震动强度的增大,覆盖层厚度对加速度放大系数的影响成份有逐渐加大的趋势;覆盖层厚度对加速度放大系数的影响程度随着等效剪切波速的增大而逐渐减弱;加速度放大系数与场地等效剪切波速和覆盖层厚度之间具有较高的拟合度的统计回归关系。由此提出了直接用场地等效剪切波速和覆盖层厚度对地震动峰值加速度进行调整的新途径。最后,就地震动峰值加速度随场地条件的调整方法,提出了有待进一步研究的问题。更多还原

【Abstract】 Based on abundant drilling data of the Xi’an avea,44 typical section planes were built according to the equivalent shear wave velocities and thickness of overlaying layer,and the peak accelerations of ground motion were calculated by the method of one-dimensional equivalent linearized earthquake response analysis corresponding to seismic ground motion with different intensites.In addition,the characteristics of ground peak acceleration amplification coefficient ks variating with site classification,equivalent shear wave velocity Vse and thickness of overlaying layer H and intensity of seismic ground motion ar were analyzed,and the conclusion that the peak acceleration adjusted according to site classification in the past should be defective is acquired.The results show that ks is decreasing when the values of Vse,H and ar are increasing.The results also show that ks is dominated by Vse more than by H,the effects of H increase gradually with the increasing of ar and reduce gradually with the increasing of Vse.Furthermore,ks should be expressed as a function depending on H and Vse.In the end,certain new methods of adjusting ground peak earthquake acceleration by controlling equivalent shear wave velocity and thickness of overlaying layer are suggested,and the problems needed to be researched more in the future are pointed out.更多还原