不同地应力下的地下硐室动态特征分析

Analysis on Dynamic Characteristics of Underground Cavern under Different In-situ Stress

采用FLAC3D对地震动荷载作用下不同地应力状态的地下岩体硐室的动态特性进行了初步分析。分析结果表明,地震荷载作用下,硐室位移随地应力侧压系数的增加明显减小,地应力侧压系数λ<1时的硐室位移量值随侧压系数的变化幅度明显大于地应力侧压系数λ>1时的情况;当侧压系数λ<1,随剪切波入射角的变化,硐室测量点位移响应先增加后减小;而当侧压系数λ>1,随剪切波入射角的增加,硐室测点位移先减小后增加,同时随地应力侧压系数的增加有减小的趋势。

The dynamic characteristics of underground rock cavern under the different in - situ stress states induced by the action of earthquake were analyzed using finite - difference program FLAC3D. The results showed that the displacement of the surrounding rock of cavern evidently decreases with the increase of in - situ stress side pressure coefficient , as well as the decreasing rate of surrounding rock displacement of cavern with increasing at the condition of λ 〈 1 are significant larger than that of λ 〉 1 ; when λ〈 1, the displacements of measured points in cavern increase then decrease with the increasing incident angle of shear wave, while, when λ 〉 1, the displacements decrease then increase with the increasing incident angle of shearwave, and the influence of incident angle on the displacements of measured points tends to decrease with the increasing in - situ stress side pressure coefficient.