水布垭枢纽地下厂房开挖支护过程三维数值模拟

Three dimensional-numerical simulation of excavation and support processes for underground powerhouse of shuibuya hydroelectric project

考虑清江水布垭枢纽大型地下厂房围岩(包括主要断层在内)的复杂地质条件,建立了其三维数值模型,对软岩置换、分步开挖及支护的施工全过程进行了数值模拟。基于计算结果,对比分析了毛洞与分步开挖支护两种情况下,若干典型断面各施工过程步的应力分布、顶拱沉降和侧墙收敛变形及其演化过程。分析表明:计算结果与现场监测信息具有较好的一致性,支护条件下该地下厂房总体上是稳定的,计算成果对后续施工与支护方案的动态设计优化具有指导意义。

A three-dimensional numerical model of the underground powerhouse of the Shuibuya project was firstly established based on the results of geological investigation. Then, the detailed construction processes, including the replacement of soft rock, excavation as well as support, were numerically simulated. The distribution and evolution of stresses and displacements around the underground powerhouse with and without support system are compared and discussed. The further analyses demonstrate that the results from the numerical simulation agree fairly well with the in situ monitoring data; and the underground powerhouse with the designed support system is globally stable. This paper provides some significant results for the dynamic design optimization of the construction and support scheme of the underground powerhouse of the Shuibuya project.