剪切波速对场地地表地震动参数的影响

Effect of Shear Wave Velocity on the Ground Motion Parameters of Site Surface

本文以江淮地区典型场地资料为原型,将土层剪切波速实测值按照一定比例进行增减,构造多种场地土层地震反应分析模型,选择Taft、E1centro和Kobe三条强震记录作为地震输入,采用一维频域等效线性化波动方法进行了土层地震反应分析。研究结果表明,剪切波速的变异性与场地地表地震动的影响程度与输入基岩地震动的频谱特性、幅值、土层结构等因素有关。地表峰值加速度随着剪切波速的增大而逐渐增大,地表加速度反应谱的特征周期随着剪切波速的增大而逐渐减小。

Based on the data from typical sites in Jianghuai Region, many kinds of soil layer sites for the seismic response is modeled by increasing and decreasing the real test values of shear wave velocity to a scale. The seismic response of the soil layer sites is calculated with the one dimension equivalent linear method in frequency domain by choosing the Taft, Kobe and Elcentro strong motion record as the earthquake input. Our results show that the effect degree of velocity variation on the ground motion is in relation to the spectral characteristic of bedrock input earthquake motion, amplitude and soil layer structure. When the shear wave velocity increases, the peak acceleration increases, however, the characteristic period of the acceleration response spectra decreases.