大型抽排水系统在富水反坡隧道施工中的应用

The Application of the Heavy-Duty Draining System to the Construction of the Rich-Watered,Adverse Grade Tunnel

锦屏二级水电站辅引3#施工支洞穿越锦屏山系中部第五出水带，地下涌水非常丰富，单点稳定涌水量达2．5万～4．5万m^3／d，汇水稳定总量在支洞开挖期间达8．5万m^3／d，在引水隧洞开挖期间达13万m^3／d。为保证支洞安全顺利贯通和主洞的正常施工，抽排水系统的设计非常关键，经过多方论证，引入了煤矿系统的水仓抽排水设计和施工，现场取得了较好效果，确保了施工生产的正常进行。着重介绍大型抽排水系统设计及针对现场实际而进行的优化设计、抽排水设备的选用，对类似工程有借鉴意义。

Owing to the fact that the No. 3 construction supplementary shaft for the 2nd-stage hydraulic power station at Jinning goes through the No. 5 water-gushing belt of the mid-section of the Jinping Mountain System,where the underground water is very rich, the steady water-gushing amount at a single-point is as much as 25000- 45000 m3/d, and the steady collected amount of water-gushing is as much as 85000 m3/d during the excavation of the branch shafts and 130000 m3/d during the excavation of the water-leading tunnel. To ensure the safe and successful cutting-through of the branch shafts and the normal construction of the main tunnel, the design of the draining system is of the greatest importance. Upon the basis of lots of investigation and studies, the design and construction methods of the dibhole draining system commonly used in coal mines are introduced, achieving a very good result at the site and thus ensuring the normal progress of the construction. The optimized design of the heavy-duty draining system specifically for the practical situation of the site and the correct choice of the proper draining equipment are elaborated in greater detail in the paper, which may provide a useful reference for other similar projects.