【摘要】 建立了高山峡谷场地的动力计算模型,分析了攀枝花地震动作用下场地水平峰值加速度(HPA)的衰减效应,研究了不同参数对场地HPA传播特性的影响。数值分析结果表明:HPA随深度增加而衰减,HPA在坡脚处比在峡谷处要低一些;在山顶处有放大效应,但放大系数比实际震害要小一些;HPA衰减程度随着阻尼比和模型深度的增加而增加,随着坡比增加而减小,且不受输入地震动峰值加速度影响;在不同频谱特性地震动作用下,当地震波的卓越频率接近计算模型的自振频率时,场地衰减程度会随之增大。更多还原

【Abstract】 The dynamic numerical model of a gorge site is established,and the depth attenuation and topographic effect of horizontal peak acceleration(HPA)of the gorge site under the Panzhihua earthquake record is analyzed.In addition,the influence of different parameters of the gorge site on propagation characteristics of seismic wave is studied.The results of numerical simulation show that HPA decreases with depth increasing,and HPA at slope toe is smaller than that at the gorge bottom;the HPA is amplified at the mountain top,but is smaller than actual earthquake record.The attenuation degree increases with damping ratio and model depth,but decreases with slope ratio;the change of peak acceleration of input earthquake has no influence on the attenuation effect due to the viscoelastic assumption.When the predominant frequency of input earthquake approaches the natural frequency of gorge site,the attenuation degree will increase.更多还原