考虑地震动空间非一致性的岩体地下洞室群 地震反应分析

 阐述人工合成考虑空间非一致性的多点地震动加速度时程步骤，提供合理的空间非一致地震动输入。在此基础上，建立一大型地下洞室群的三维数值计算模型，分析一致与非一致两种地震动输入情况下该地下洞室群的地震响应特征。研究结果表明，洞室群地震响应与激振源的位移时程曲线形式接近，表明围岩的惯性效应可以忽略；地震波幅值对于地下洞室地震响应具有决定性作用，而地震动的空间非一致特性对于讨论的轴向长度水平(轴线长度尺寸为300～400 m)的地下洞室的破坏未产生不利影响。因此，在进行类似的岩体地下洞室地震动安全评价时可以不考虑地震动空间非一致性的影响。

SEISMIC RESPONSE ANALYSIS OF AN UNDERGROUND CAVERN GROUPS IN ROCK SUBJECTED TO SPATIALLY NON-UNIFORM SEISMIC GROUND MOTION

Procedures for artificial simulation of multi-point seismic acceleration histories with consideration of spatially non-uniform seismic ground motion are demonstrated to provide reasonable ground motion input for the numerical models. By establishing three-dimensional numerical model of underground rock cavern groups，seismic responses of the underground cavern groups under spatially uniform and non-uniform ground motion are carried out. It is shown that：(1) seismic response of the cavern groups is very similar to the time-history curves of displacement of the exciting sources，which indicates that the inertial effect of the rock mass can be ignored；and (2) seismic response mainly depends on the amplitude of the seismic waves；the spatial non-uniform effect has no negative impact on the underground cavern groups under the axial length ranging from 300 m to 400 m. Spatially non-uniform seismic ground motion，therefore，cannot be taken into account in the seismic safety assessment of the similar underground rock cavern groups.