大型水电工程建设岩石力学工程实践

中国三峡工程以及金沙江下游4座梯级水电站工程规模巨大,地质条件复杂,在建设过程中遇到了诸多岩石力学难题。结合这5座大型水电工程建设的岩石力学工程实践经验,对高边坡与滑坡岩体工程问题、坝基坝肩岩体工程问题、地下洞室群岩体工程问题、高地应力与高地震烈度问题的处理措施进行了回顾,介绍了三峡船闸高边坡、溪洛渡高边坡以及乌东德高位自然边坡的稳定技术,三峡大坝和溪洛渡拱坝建基岩体抗滑稳定技术,三峡枢纽地下厂房和向家坝水电站地下厂房的围岩稳定技术以及巨型滑坡综合治理等关键技术。在此基础上提出了大型水电工程岩石力学研究工作的通用技术路线:重视勘探与工程地质力学模型分析,合理界定岩体的介质模型及等效连续参数,并以地应力作为初始分析条件,采用适宜的连续或非连续介质力学分析方法进行岩体稳定分析,从而确定岩体加固方案,实施监测并实现反馈设计。

Engineering practice of rock mechanics in large-scale hydropower projects

The construction of China Three Gorges Project and the four cascade hydropower stations in the lower Jinsha River encountered a great number of challenged rock mechanics problems due to their large scale and the complex geological conditions. According to the experiences accumulated in rock mechanics engineering practice in the above five large-scale hydropower projects, we reviewed the countermeasures towards the high side slope and landslide problems, dam foundation and dam abutment rock engineering problems, underground cavern groups rock engineering problems and high geo-stress and high seismic intensity problems. A series of key technologies adopted during the construction of these five hydropower stations were reviewed, such as the technologies for the stability of high side slopes of Three Gorges ship lock, Xiluodu and Wudongde, anti-sliding technologies for the Three Gorges dam and Xiluodu arch dam foundation rock masses, technologies for the stability of the surrounding rock masses in the underground caverns of Three Gorges and Xiangjiaba Hydropower Stations, and the comprehensive prevention technologies for giant landslides. Based on these practice experiences, we proposed a common technical route for the rock mechanics research works in large hydropower projects. First we should pay attention to the investigation and engineering geological mechanical model analysis. Then the rock masses should be described with reasonable medium model and equivalent continuum parameters. With the geo-stress as the initial analysis conditions, the rock masses stability can be assessed with appropriate continuum or non-continuum mechanics methods in order to determine the reinforcement schemes for the rock mass. Feedback analysis must be done according to field monitoring.