采用三维弹塑性损伤有限元数值分析法对向家坝地下厂房洞群围岩稳定性进行了分析论证。探讨了围岩力学参数以及围岩力学模型对洞周塑性区、应力与位移的影响，通过多种方案计算和比较，论证了向家坝地下厂房大型洞室参数、支护形式、支护参数的合理性。综合分析后认为：向家坝水电站右岸地下厂房洞室群的成洞条件较好，围岩基本是稳定的，经过锚喷支护后整体稳定是有保证的。

The stability of surrounding rock of Xiangjiaba Hydro- power Stations underground powerhouses is demonstrated by the method of three- dimensional elastic and plastic damage elements. The effects of the mechanical parameters of the surrounding rock and mechanical model on the plastic region, stress and displacement are discussed. The rationalities on chambers parameters, supporting patterns and relative supporting parameters of underground powerhouses are verified. Comprehensive analyses lead to the following conclusions: the rock condition is good for excavating chambers in the right bank underground powerhouses of Xiangjiaba Hydro- power Station; surrounding rock is generally stable and unitary stability can be guaranteed after anchorage and gunited support.