富水圆砾地层盾构隧道联络通道加固技术研究

Case study on soil reinforcement method for the cross-passage construction of shield tunnel in water-rich round gravel stratum

联络通道施工是盾构隧道施工中的事故多发阶段,选择合理的土体加固方式提高周边土体的稳定性是保证联络通道施工安全的关键环节。本文介绍了联络通道常见的施工方法和加固方式,并针对南宁市富水圆砾地层特性,结合南宁地铁2号线三苏区间联络通道的施工,对适应该地层的盾构隧道联络通道加固工法进行比选分析,最终采用地下连续墙加膏浆注浆技术进行预加固处理。通过对加固后的地层沉降变形、地下水位和联络通道净空收敛等实测数据的分析,验证了地下连续墙加膏浆注浆对圆砾地层注浆加固的可靠性,为今后富水圆砾地层盾构隧道联络通道施工提供了一定的参考。

The connecting-passage construction is an accident-prone phase in the construction of shield tunnel and improving the stability of the surrounding soil by adopting efficient reinforcement methods is the key to ensure the connecting-passage construction safety. This paper presented the common reinforcement methods of connecting-passage,and according to the characteristics of Nanning water-rich round gravel stratum a detailed comparison analysis is made of the reinforcement methods appropriate for the formation of the connecting-passage of shield tunnel. Finally the prereinforcement method of lain concrete continuous wall and paste-slurry technology is carried out in the connecting-passage of Sansu Tunnel in Nanning subway line 2. The ground surface deformation,the groundwater level,the deformation of the connecting-passage and associated information were monitored during the construction and the results measured were analyzed. The practice showed that lain concrete continuous wall and paste-slurry technology can ensure the safety of the connecting-passage construction,which may provide certain reference for similar projects.