考虑复杂断层及岩脉的地下硐室群开挖步序优化研究  

Study on the Optimization of Excavation Steps of Underground Caverns with Complex Faults and Dikes

作　　者：耿必君 张祥富 袁涛 钟聚光 陈天乐 GENG Bijun;ZHANG Xiangfu;YUAN Tao;ZHONG Juguang;CHEN Tianle(Hunan Pingjiang Pumped Storage Power Station Co.,Ltd,Yueyang 414500,China)

机构地区：[1]湖南平江抽水蓄能有限公司

出　　处：《人民珠江》2019年第12期116-122,共7页Pearl River

摘　　要：以某拟建抽水蓄能电站地下厂房硐室群为例,考虑复杂断层及岩脉,采用三维数值方法对不同开挖步序下厂房围岩变形及应力力学响应展开研究,并比选最优方案。研究结果表明:厂房硐室在四种开挖步序工况下,围岩位移场相差不大,硐室围岩的水平位移极大值出现在边墙中部,铅直方向的沉降极大值出现在硐室围岩拱顶,卸荷回弹位移极大值出现在洞室底板中部;主厂房上游边墙局部部位出现拉应力区,方案2引起的拉应力区范围最小,方案3最大;七步开挖方案条件下的塑性区体积均小于六步开挖方案的结果,表明主厂房采用七步开挖方法有助于减少洞室围岩的塑性区分布;在考虑复杂断层及岩脉的情况下,4种施工步序方案均为可行方案,方案2为最优方案。研究成果可为抽水蓄能电站地下厂房硐室群开挖施工提供指导。Taking the underground powerhouse caverns of a proposed pumped storage power station as an example,and considering the complex faults and dikes,this paper uses the 3D numerical method to study the deformation and stress response of the surrounding rock of the powerhouse under different excavation steps,and make the optimal scheme after comparison.The results show that with the powerhouse caverns under the four excavation steps,the displacement field of surrounding rock is not much different.The maximum horizontal displacement of the surrounding rock appears in the middle of the side wall,the maximum vertical settlement appears at the dome of the surrounding rock,and the maximum unloading rebound displacement occurs in the middle of the floor of the cavern;the tensile stress zone appears in the local part of the upstream wall of the main building,and the range of the tensile stress zone in the Scheme 2 is the smallest,and the Scheme 3 is the largest;the area of the plastic zone under the seven-step excavation is smaller than that of the six-step excavation,indicating that the seven-step excavation method of the main building can reduce the distribution of plastic zone on the surrounding rock of the cavern;based on complex faults and dikes,the four excavation step schemes are feasible,among which the Scheme 2 is the optimal.The research results can provide guidance for the excavation construction of the underground powerhouse caverns of the pumped storage power station.

关 键 词：地下厂房 断层及岩脉 围岩稳定性 开挖步 数值分析 

分 类 号：TV36[水利工程—水工结构工程]