锦屏二级水电站1#引水隧洞绿泥石片岩洞段处理技术与应用

Technology for treatment of chlorite schist section in No. 1 diversion tunnel of Jinping II Hydropower Station and its application

针对锦屏二级水电站1#引水隧洞绿泥石片岩洞段施工期间出现塌方、围岩变形松弛、初期支护围岩变形收敛缓慢、普通水泥固结灌浆无法达到设计要求等技术难题,及时调整优化设计参数和施工方案,采取了二次扩挖、超前支护、加强系统支护、钢拱架支护、锚索支护、细水泥灌浆等综合工程措施,成功地解决了绿泥石片岩软岩洞段围岩抗变形稳定问题。

Aiming at the technical problems occurred during the construction of the chlorite schist section in No. 1 diversion tunnel of Jinping II Hydropower Station,such as collapse,deformation and relaxation of the surrounding rock,deformation and slow convergency of the initially supported surrounding rock,the conventional cement consolidation grouting that can not meet the relevant design requirement,etc.,the design parameters and the construction scheme are adjusted and optimized in time,i. e.the comprehensive engineering measures of the secondary enlarging excavation,advanced support,reinforced systematic support,steel arch support,anchor-cable support,fine cement grouting,etc. are taken,and then the problem from the ant-deformation stability of the soft rock—chlorite schist section in the tunnel is successfully solved.