隧底煤层段地基钢花管注浆加固施工工艺研究

Study on Construction Technology of Grouting Reinforcement for Foundation Steel Tube in Tunnel Bottom Coal Seam

针对隧底软弱围岩处理,国内传统施工工法为换填法、常压注浆法、旋喷桩加固法、锚杆法、钻孔桩加固法,根据以往处理效果,其中换填法、常压注浆法、旋喷桩加固法、锚杆法对隧道基底承载力提高作用有限,不能有效提高基底承载力;钻孔桩加固法,能有效提高隧道基底承载力,但因隧道内施工条件有限,施工难度大、进度慢、投入成本较高,且对周边围岩扰动较大,存在一定的安全风险。本文结合成贵铁路观音山隧道煤系地层段隧底采用的钢花管注浆施工工艺解决了围岩地基承载力不够的难题,仅供大家参考。

For the treatment of weak surrounding rock at the tunnel bottom,the traditional construction methods include replacement filling method,atmospheric pressure grouting method,jet grouting pile reinforcement method,anchor rod method,and bored pile reinforcement method.According to the previous treatment effect,the replacement filling method,atmospheric pressure grouting method,jet grouting pile reinforcement method and the anchor rod method have limited effect on the bearing capacity of the tunnel foundation,and can not effectively improve the bearing capacity of the foundation;the bored pile reinforcement method can effectively improve the bearing capacity of the tunnel foundation,but due to the limited tunnel construction condition,the construction difficulties,slow progress and high input cost,and the surrounding rock is disturbed greatly,there is a certain safety risk.This paper solves the problem of insufficient bearing capacity of surrounding rock foundation by combining the steel tube grouting construction technology used in the tunnel bottom of the coalsediment section of Guanyinshan Tunnel of Chenggui Railway.It is for your reference only.