地震作用下大型地下洞室群位移特征的若干影响因素分析

利用三角级数叠加法,考虑到基岩场地的深度衰减效应,生成了大型地下洞室群非平稳人工地震动加速度时程。然后利用动力时程分析法,对大渡河某水电站大型地下洞室群进行了非线性地震动力响应分析,研究在不同频谱人工地震波作用下地应力特征、峰值加速度和频谱对大型地下洞室群位移特征的影响。分析结果表明,地下洞室群相对位移随着侧压力系数和峰值加速度的增加而略有增加,不同频谱的地震波有着截然不同的位移特征。研究成果对高地震烈度区地下洞室群抗震稳定性分析具有一定的借鉴意义。

Some influence factors on displacement characteristics of cavern group under strong earthquake

Considering the depth attenuation effect of bedrock site, the artificial seismic waves with different spectra for large-scale underground cavern group are created by trigonometric series superposition. The time-history nonlinear dynamic response analysis method is used to simulate the seismic response to the large-scale underground cavern group of some hydropower station in Southwest China; and the displacement characteristics are studied in the case of different geostresses, peak accelerations and spectra. The results show that the relative displacements of underground cavern group increase with lateral stress coefficients and peak accelerations. Furthermore, waves with different stectra result in distinct displacement characteristics. The present work could be used as a primary guidance to the aseusnuc design for underground caverns.