基于FLAC~(3D)的某水电站大型地下洞室群开挖及锚固效应数值分析

根据地下洞室开挖和锚固施工方法,采用FLAC3D数值分析程序,对某大型水电站地下厂房复杂洞室群开挖过程进行了动态模拟,分析了在有、无支护条件下洞室周边围岩二次应力场、位移及破坏区分布规律和变化特征,说明采用隐含断层复合单元模拟断层、cable结构单元模拟锚杆、薄层实体单元模拟喷层能较合理反映地下洞室分期开挖实际力学作用机理.计算结果表明,该洞室群在洞室布局、开挖顺序和支护参数等方面是合理的,认为在局部加强支护的条件下,洞室的整体稳定可以得到保证.

Numerical analysis of excavation and anchorage effect on complex underground caverns of a hydropower station with FLAC3D

Based on the process of excavation and anchorage of underground caverns,FLAC3D numerical modeling technique is used to dynamically analyze the distribution rules and variation features of the second stress field,displacement field and plastic zones before and after construction of anchorage support; it is shown that the complex element of connotative fault simulating geologic faults,cable structure element simulating anchor bar and anchor cable,thin-layer solid element simulating concrete liner can reasonably reflect factual mechanism of excavation by stages.The computation result shows that the opening's layout,construction sequence and support parameters are rational; the stability of whole caverns will be guaranteed with local supports strengthening.