断层等软弱地质结构面是控制地下洞室群围岩稳定的主要因素.以某水电站大型地下厂房为例,采用三维非线性有限元法分析了地下洞室群的围岩稳定,建立了考虑优势断层结构面的地下洞室群三维有限元模型,对比分析了有、无支护方案下洞周围岩位移场、应力场及塑性区分布.结果表明,洞周围岩变形受断层影响显著,断层贯穿部位多发生应力突变,断层出露部位塑性区分布范围较大;施加支护方案后,围岩变形得到了有效控制,应力集中和围岩塑性区分布范围均有所减小.%The weak geological structure plane is an important factor to control the stability of surrounding rock masses of underground caverns,such as the faults.Taking a large underground powerhouse as an example,the stability of its surrounding rock masses is analyzed by using three-dimensional nonlinear finite element method.The three-dimensional finite element model considering dominant fault structures of underground caverns is established to analyze the displacement field,stress field and plastic distribution in surrounding rock mass with supporting or without supporting respectively.The results show that,(a) the deformation of surrounding rock is obviously affected by faults,the stress mutation mostly appears in the area where the fault runs through,and the plastic area in the exposed part of fault is larger;and (b) the deformation of surrounding rock has been effectively controlled when the supporting is applied,and the stress concentration and the distribution of plastic area are also decreased.
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