隧道岩溶地层超前预注浆技术应用研究

Research on Application of Advance Pre-grouting Technology for Tunnel with Karst Stratum

为避免隧道在施工过程中发生瓦斯爆炸、岩溶、断层突水突泥、软弱地层失稳坍塌,文中依托成贵高铁白杨林隧道工程,考虑隧道实际地质特点,基于设计图纸与现场情况,确定采用全断面超前预注浆技术作为白杨林隧道岩溶地层处治措施。隧道岩溶地层超前预注浆技术应用结果表明,该项技术需要基于具体的地质、水文条件和现场实施情况调整注浆参数,硫铝酸盐水泥浆液凝结时间短,需要添加缓凝剂才能延长初凝时间,其注浆效果劣于普通硅酸盐水泥单液浆,且周边帷幕孔采用双液浆可以有效封堵地下水。

In order to avoid the occurrence of gas explosion,karst,water inrush from faults,and weak stratum instability and collapse during tunnel construction,relying on the Chengdu-Guiyang high-speed railway Baiyanglin tunnel project,the actual geological conditions of the tunnel are taken into consideration to determine the treatment measures for tunnel karst stratum.Based on the design drawings and site conditions,the full-face advanced pre-grouting technology is determined to strengthen the tunnel.The application results by grouting in advance technology for tunnel in karst strata shows that the technology needs to adjust grouting parameters according to the specific geological,hydrologic conditions and field implementation.The setting time of sulphur aluminate cement mortar is short,and it needs to add retarder to extend the initial setting time.The grouting effect of the sulphur aluminate cement is inferior to single silicon cement grout,and the groundwater can be effectively blocked by pouring double grout curtain into the surrounding holes.