高地应力与强渗透水压下软弱围岩支护

为了解决锦屏Ⅱ级水电站引水隧洞工程中高地应力和高渗透水压力条件下破碎带洞段软弱围岩合理支护的关键技术问题,应用弹塑性基于流固耦合原理的三维快速拉格朗日有限差分法,分析比较了不同支护方案下隧洞围岩塑性区分布范围与变形特征.研究结果表明,在高地应力和高渗透水压力条件下,根据将围岩视为承载结构以充分发挥围岩承载能力的设计理念,围岩支护采用可使围岩与支护结构充分地联合承载的喷锚支护、固结灌浆和混凝土衬砌的联合支护型式,这是解决高地应力与强渗透水压力联合用下软弱围岩稳定性问题的有效途径.

Support for weak surrounding rock under high geo-stress and high seepage pressure condition

The determination of reasonable support for weak zone of diversion tunnel under high geo-stress and high seepage pressure condition is a challenging key problem in the construction of Jinping Ⅱ hydropower station. In order to solve the problem, reasonable support types for weak zone of the diversion tunnel are compared using FLAC~(3D) ( fast lagrangian analysis of continua in 3 dimensions) numerical program based on coupled fluid-mechanical theory. According to the analysis results, recommended scheme of support designed for weak zone of the diversion tunnel under high geo-stress and high seepage pressure condition is proposed. The analysis results indicate that the combinational support type, including bolting, shotconcrete, consolidation grouting and lining is effective to solve the stability problems of surrounding rock of weak zone under high geo-stress and high seepage pressure condition according to the design idea of regarding surrounding rockmass as the main structure for carrying load or making full use of load bearing capability of surrounding rockmass.