大断面硐室围岩塑性区变形及稳定性控制

Plastic Deformation and Stability Control of Large Section Cavern Surrounding Rock

针对蓄水电站排水大断面硐室围岩塑性变形失稳问题,采用现场调研与弹塑性理论及损伤理论相结合的方法,建立了支护作用下硐室围岩变形力学模型,推导出了围岩塑性区半径及其变形解析解,并运用算例分析了围岩塑性区半径及变形演化规律。同时,采用钻孔窥视仪探测了大断面硐室围岩破坏特征,提出了采用浅部锚固-深部悬吊与注浆相结合的支护方法对大断面硐室围岩的稳定性进行控制。经现场实践表明,该方法能够使大断面硐室围岩变形及整体性得到有效控制,围岩的稳定性得到保障。

In view of the deformation and instability characteristics of large section cavern surrounding rock, based on filed investigation, elastoplastic theory and damage theory, mechanical model of surrounding rock deformation of cavern with support was established, and the analytical solution for radius and deformation of plastic zone of the cavern surrounding rock were derived.Through example analysis, the radius of plastic zone and deformation evolution laws of surrounding rock were analyzed. Failure characteristics of surrounding rock were detected by borehole peep meter. Support method of shallow anchoring and deep suspension and grouting was proposed for controlling stability of carven surrounding rock. Field application showed that the method can effectively control deformation and integrity of surrounding rock, and stability of surrounding rock was guaranteed.