积石峡水电站导流洞交叉段水平层状岩体稳定数值仿真分析

Numerical Analysis on the Stability of Horizontal Layered Rock Masses in the Cross Section of Diversion Tunnel in Jishixia Hydropower Station

积石峡水电站导流洞及中孔泄洪洞交叉段设计体形复杂,且顶拱上方有一3～10 cm厚的软弱夹层穿过,围岩整体稳定性差,安全问题突出。为确保交叉段顺利贯通及施工安全,拟定了5种开挖和支护方案,采用数值仿真分析系统分析比较了不同开挖和支护方案下施工期围岩和支护的稳定性,确定了交叉段的开挖方式和支护技术措施,经实际应用,效果良好。

The shape design of the cross section of diversion tunnel and middle spillway tunnel in Jishixia Hydropower Station project is complex, and there is a week intercalated layer with a thickness of 3-10 m in the crown area, the stabilities of surrounding rock masses are poor. For guaranteeing the safe construction, five excavation and support programs arc developed and the stabilities of surrounding rocks and support under different program are simulated numerically and compared to determine the final construction program. The actual excavation shows that the program is feasible.