中天山隧道节理密集带超高压裂隙水处理技术

Treatment Techniques for an Ultrahigh Pressure Bearing Fissure Water at a Developed Joint Zone in the Zhongtianshan Tunnel

中天山隧道施工过程中遇到了节理密集带超高压裂隙水,水压力达6.3 MPa,超前探孔单孔出水量为500 m3/h,造成了淹井灾害,由于施工中采取了"注浆减排、降水降压"的处理方案,取得了预期的注浆堵水效果,确保了隧道的安全顺利施工。文章详细阐述了中天山隧道的注浆和排水的设计方案和设计参数,以及"高压补给冲击钻进"成孔和"同掌子面边泄边注"等关键技术,对P-Q-t曲线、钻孔出水量、检查孔出水量、检查孔稳定性,以及注浆效果进行了分析总结。

During construction of the Zhongtianshan tunnel, a developed joint zone was encountered with water pressure of up to 6.3 MPa and a water inflow of 500 m3/h/probing hole, causing a flood disaster in the tunnel. In this context, the principle of ＂drainage reduction by grouting and depressurizing by dewatering＂ was adopted. The grouting and dewatering design parameters, the new hole-drilling technology with ＂high pressure percussion drilling,＂ and the new grouting technology with simuhaneous grouting and discharging at the same working face are described in this paper. Prospective effects of water blocking by grouting are achieved based on the analysis of a P-Q-t curve, water inflow in the drilling hole, water inflow in the testing hole, and stability in the testing hole, ensuring the success of tunnel construction.