中文摘要：

猴子岩水电站地下厂房洞室群具有高地应力、低强度应力比的特点,在施工过程中出现严重的变形破坏现象。结合地质、监测、检测及施工资料对施工期围岩的变形与破坏特征进行分析,分析结果表明：主厂房、主变室及尾调室围岩位移大于50 mm的测点分别占17.2%,27.3%和9.4%,三大洞室围岩变形处于较大水平,远超其他电站同期水平。最大位移出现在III1类围岩处,表明高地应力条件下,较完整硬岩产生的卸荷回弹变形较大,岩石本身破坏产生的变形所占比重增加。围岩变形深度为5-15 m,最大可达23 m,相对较大;围岩变形与开挖卸荷关系密切,呈＂阶跃式＂发展。围岩变形破坏以应力重分布起主导作用的应力驱动型为主,由结构面不利组合控制的重力驱动型不再占主导地位。研究猴子岩地下厂房洞室群围岩变形破坏机制对其施工及运营安全具有重要的工程意义。

英文摘要：

The surrounding rock mass of the underground caverns at Houziyan hydropower station is under high ground stresses and has a low strength-to-stress ratio,leading to severe rock deformations and failures in the process of construction. The deformation and fracture characteristics of the surrounding rock mass were analyzed according to the geological conditions,the data from monitoring and geophysical detection,and the construction process. The proportions of the measured points with the displacements greater than 50 mm in three main caverns are 17.2%,27.3% and 9.4% respectively. The deformations of the surrounding rock mass of the underground caverns are much greater than the ones of the underground caverns at other stations in the same period. The largest displacement is in the rock of category III1,which indicates that the deformation of rebound of the relatively complete and hard rock due to unloading under high ground stress are quite large. The depths of surrounding rock deformation reache 5 to 15 m,even up to 23 m. The deformation of surrounding rock was found to be closely related to the excavation with a stepped process of development. The deformation of the surrounding rock is largely stress driven with the stress redistribution playing the dominant role and the one to be gravity driven controlled by the adverse combination of structural planes played less roles.