水平后退式注浆技术在高速铁路隧道穿越富水砂砾地层中的应用

为解决宝兰客专石鼓山隧道DK639+612.9处突水、涌水、涌砂、塌方等危害,在富水饱和砂砾地层施工中采用水平深孔后退式二重管注浆工艺,隧道开挖轮廓线外3 m范围内局部布孔注浆,封堵地下水和加固围岩,从注浆后检查孔检查及开挖过程中揭示情况,深孔后退式二重管注浆超前止水及加固围岩效果良好,能确保顺利、安全穿越富水饱和砂砾地层。在确保施工安全和质量的前提下,施工中创造了Ⅵ级围岩地段单月开挖支护40 m的进度指标,为富水饱和含砂砾层地段及类似地段高风险隧道的施工建设积累了重要经验。

The Application of Horizontal Backward Grouting in High-speed Railway Tunnel Passing through Water-rich Gravel Layer

To solve such problems as water burst,sand gushing and collapse encountered at DK639 +612. 9 of Shigushang tunnel on Bao-Lan dedicated passenger railway line, the deep hole grouting performed horizontally and backwardly with double-pipe is employed in the tunnel construction in water-rich gravel layer with grouting holes arranged within 3 m out of the tunnel excavation profile to block underground water and reinforce surrounding rock. The inspection after grouting and during excavation shows that this grouting method is effective in advance water blocking and rock reinforcement to pass through water-rich gravel layer. The site work breaks a 40 m monthly record in VI surrounding rock section and accumulates significant experiences in similar high risk tunnel construction in water-rich gravel bed area.