介绍彭水水电站地下主厂房洞室施工过程中高边墙围岩的变形破坏特征、相应的加固处理措施以及围岩监测成果等;在此基础上,开展主厂房围岩施工期的动态反馈分析。研究结果表明:对于陡倾角层状岩体中开挖的大型地下洞室群,围岩中分布的软弱结构面和岩层层面对上、下游边墙的变形与稳定起着控制性作用,陡倾角、顺向岩层组合的高边墙其变形失稳模式以典型的滑移破坏为主;而陡倾角、逆向岩层组合的高边墙则以沿层面的张裂、折断、倾倒变形后的坍塌破坏为主。通过开展施工期围岩监测反馈分析,为彭水水电站地下厂房的动态设计和信息化施工提供了重要依据。
The deformation and failure characteristics of the surrounding rock of the high side wall of underground powerhouses of Pengshui Hydropower Station, corresponding supporting and processing scheme and the monitoring results, are described. Then dynamic feedback analysis is performed and the result is given. The result shows that the stability of high side wall is very critical when excavating large underground caverns in steeply dipped sedimentary rock strata; the deformation and stability of the surrounding rock is primarily dominated by weak structure plane and bedding plane. For the high side wall with steep dip angle and consequent rock strata, the deformation and failure mode of surrounding rock are typical sliding along the bedding plane; and for the high side wall with steep dip angle and obsequent rock strata, the deformation and collapse are caused by tension crack, break off and toppling. The results of feedback analysis based on the deformation monitoring data can provide important references to dynamic support design and information construction of the underground powerhouses.