高水头地下水对长水工隧洞施工的影响探讨

Influence analysis of high head underground water on construction of long hydraulic tunnel

牛栏江-滇池补水工程金奎地隧洞和大五山隧洞施工过程中发生了突水涌泥事故,对施工产生了较大影响。根据地质情况分析,突水涌泥事故均由岩溶裂隙水引起,具有水头高、流量大的特点。经研究,决定调整隧洞线路,并采用超前地质预报、超前排水减压、超前固结灌浆、超前管棚支护、短进尺、弱爆破、及时衬砌的施工方案。施工实践表明,所采用的施工方案合理可行,及时有效地处理了事故,并保证了后续施工的顺利进行。

In the construction of Jinkuidi tunnel and Dawushan tunnel of Niulan River - Dianchi Lake Water Supplement Pro- ject, the accidents of water gushing and mud inrush happened and seriously influenced the construction. According to geological analysis, the accidents were caused by karst fissure water with the characteristics of high water head and large discharge. After a- nalysis, the tunnel line was adjusted and the construction schemes of geological forecast, pre - discharging for reducing water pressure, pre - grouting for consolidation, pre - support by pipe - shed, short - distance advancing, slight blasting, timely lining were determined. The construction practice showed the construction scheme was reasonable and feasible, so the accidents were treated successfully and the smooth construction was guaranteed.