暗挖隧道全断面止水帷幕施工技术研究

Study on Construction Technology of Full Section Water Stop Curtain in Dug Tunnel

为解决溶蚀破碎地层和富含地下水地质条件建造暗挖隧道难题,提出一种全断面止水帷幕加固隧道轮廓线外围岩施工方法,重点解决隧道施工过程渗漏水难题。全断面止水帷幕是对隧道拱顶、两侧、仰拱外侧围岩进行全断面注浆加固处理,加固方向沿隧道开挖方向进行,有效封堵隧道前方渗漏水。设置止浆墙作为注浆的基准面,止浆墙上布设注浆孔和注浆小导管。帷幕注浆材料采用硫铝酸盐水泥并对注浆效果进行评定。根据不同地质条件使用不同的注浆方式,地质条件较差时采用前进式注浆,当围岩较为完整时采用后退式注浆工艺。经隧道测量数据表明,采用全断面止水帷幕注浆方法能满足复杂地质条件隧道施工需要。

In order to solve the problem of tunnel excavation in dissolved broken strata and rich groundwater geological conditions,a construction method of full-section water seal curtain to strengthen the surrounding rock outside the tunnel contour line is proposed,which focuses on solving the problem of water leakage during tunnel construction.The full-section water stop curtain is used to reinforce the surrounding rock of the tunnel arch,both sides and invert,and the reinforcement direction is carried out along the tunnel excavation direction to effectively block the leakage in front of the tunnel.The stop wall is used as the base surface of grouting.Grouting holes and small grouting conduits are arranged on the grouting wall.Curtain grouting material is sulfoaluminate cement and the grouting effect is evaluated.Different grouting methods are used according to different geological conditions.When the geological condition is poor,forward grouting is used.When the surrounding rock is relatively intact,the backward grouting process is adopted.The tunnel measurement data show that the grouting method of full section water curtain can meet the needs of tunnel construction under complex geological conditions.