考虑岩土介质随机特性的工程场地地震动相干函数研究

Effect of random media on coherency function of seismic ground motion

将随机结构正交展开理论和随机振动分析的虚拟激励原理运用于场地波动有限元分析,形成了一种可以考虑岩土介质随机特性对工程场地地震动相干函数影响的分析方法。实例分析表明,非严格均匀分布的随机介质场地对场地表面的迟滞相干函数值有重要影响,这种影响可由场地的随机影响因子来衡量,在进行工程场地地震动随机场研究时应当考虑场地介质随机特性的影响。

With the introduction of the pseudo-excitation method and the orthonagal expansion method into the wave finite elememt analysis, a stochastic wave analysis method of complex site is presented in this paper and the effect of random site media on the coherency function of the ground motions is studied. Numerical examples are shown that stochastic media of the site tends to reduce the lagged coherency function, which can be measured by stochastic factor of local site. This phenomena is indicated that randomness of the site media should be considered in coherency function research.