大型地下洞室群地震水平加速度传播特征研究

Horizontal seismic acceleration propagation characteristics of large-scale underground cavern group

考虑了高山峡谷基岩场地的深度衰减效应,假设地震危险性分析提供的水平峰值加速度的所在位置,选用攀枝花—会理地震波,通过基线校正和高频滤波作为实际地震动输入,利用FLAC3D软件对某水电站大型地下洞室群进行了地震水平加速度传播特性的研究。数值分析结果表明,厂房周围监测点水平加速度时程和输入地震水平加速度时程相似,但存在0.08～0.12s的滞后时差,输入地震动水平峰值加速度向上传播时具有放大效应,在洞室群附近放大两倍左右。所得结果对大型地下洞室群地震动传播特征问题研究具有一定的参考意义。

The depth attenuation effect in gorge bedrock site was considered,and the location of horizontal peak acceleration provided in the seismic hazard analysis report was assumed.One of the Panzhihua-Huili earthquake records,by baseline correction and high frequency filtering,was selected as the actual seismic input for numerical simulation on horizontal seismic acceleration propagation of large underground cavern group in some hydraulic power station by software FLAC3D.The results show that the time history of horizontal accelerations around caverns are similar to that of input seismic acceleratioo but legs behind about 0.08~0.12s with the input record.The input peak acceleration can be amplified during vertical propagation,with about twice amplification around caverns.This research results can give a reference to the study on the horizontal seismic propagation of large-scale underground cavern group.