泸定水电站3号泄洪洞出洞开挖支护

Excavation and Support for the Outlet of No.3 Spillway Tunnel in Luding Hydropower Station

泸定水电站3号泄洪洞出口洞段岩体裂隙发育且风化严重,围岩总体Ⅳ类偏差,局部为Ⅴ类,围岩自稳能力差;受前期出口左侧山体边坡塌方影响,出洞过程中妥善解决洞室左右侧偏压是确保安全出洞的关键。为此,介绍了在出洞施工的前期准备、开挖和支护中所采取的措施。通过采取相关措施,实现了出口洞段的安全贯通。

The rock mass in the outlet section of No. 3 spillway tunnel in Luding Hydropower Station are fractured and weathered and the class of surrounding rock is poor IV in general and V class in some areas. The stability of the surrounding rock is poor. Caused by the left slope landslide, the unbalanced pressure from the two sides of the tunnel is also the key to ensure the safe excavation. The measures adopted in preparation, excavation and support are introduced in detail. The measures guarantee the safe excavation of the outlet section.