向家坝变顶高尾水隧洞施工期围岩稳定性分析

摘要

As China's hydropower construction to march west,the emergence of a more large underground cav-erns.As one of its representatives.Xiangjia dam varied roof height tailrace tunnel which is more complex geo-logical conditions,rock around the hole layered sandstone body distribution,JOINTED more developed,espe-cially cylindrical blocks layered structure of the top arch of rock formed by cutting and joints poor stability of the structure,coupled with varied roof height tailrace tunnel span and sidewall height greater than the cross-sectional size becomes the top domestic and international existing tailrace tunnel project.Therefore ,to become the top Xiangjia dam high tailrace tunnel surrounding rock stability analysis ,evaluation and maintenance of surrounding rock stability,and by rock deformation prediction analysis may buckling modes and scope of the project to ensure the smooth,effective and rational exploitation underground space is of great significance,but also to gain experience for other similar projects.%随着我国水电建设向西部的进军, 涌现出了更多的大型地下洞室工程. 作为其代表之一. 向家坝变顶高尾水隧洞所处地质条件较复杂, 洞周围岩为层状分布的砂岩体, 节理裂隙较发育, 尤其是顶拱围岩的层状结构面与节理切割形成的柱状块体结构的稳定性较差, 加之变顶高尾水隧洞跨度和边墙高度较大, 超过了国内外现有变顶尾水隧洞工程的断面规模. 因此, 开展向家坝变顶高尾水隧洞围岩稳定性分析, 评价和维护围岩稳定性, 并通过变形预测分析可能的岩体失稳模式和范围, 对确保工程顺利进行、 有效合理地开发地下空间具有十分重要的意义, 同时也能为其它类似工程积累经验.