西南某水电站厂房平洞围岩变形破坏特征分析

Analysis About the Sorrouding Rock Damage Characteristics of the Adit in a Southwest Hydropwer

西南某水电站厂房平洞CPD1岩性组合较为复杂,且片理面发育。根据现场调查结果显示,洞室围岩变形破坏特征主要包括三种类型:结构型破坏、构造—应力型破坏、应力型破坏。主洞围岩总体稳定性良好,部分洞段出现掉块及劈裂倾倒破坏;支洞开挖方向与片理面方向小角度相交,围岩总体自稳性较差,在高地应力情况下出现严重的弯折内鼓现象,需采取一定的支护措施。

The adit CPD1 of a hydropower station in the southwest whose lithology is more complicated contains a lot of schistosity plane. Based on the site survey results, the main characteristics types of surrounding rock deformation and failure include structural damage, structural-stress damage and stress damage. Except some holes appear chip off-falling and the splitting dumping damage, the general stability of surrounding rock is good. However, when the direction of tunnel excavation and schistosity plane direction are small angle intersecting, the overall stability of surrounding rock is poorer. Especially severe bending inner drum phenomenon will be come out under the condition of high ground stress, it is necessary to take certain support measures.