地铁运维区间保护区明挖隧道施工技术

Construction Technology of Open-cut Tunnel in Protection Zone of Subway Operation and Maintenance

江东大道提升改造工程(河庄大道西-青六路东)项目中青六路~青东一路隧道全长853m,为实现保护区内地铁扰动较小的同时还兼顾施工质量,通过分析设计图纸、周围环境以及工程地质状况,总结形成地铁保护区内明挖隧道施工保护措施,有效解决保护区内明挖隧道施工的难题。采用SMW工法桩结合MJS桩在隧道临近已建结构物变截面处进行补强加固,封堵墙基坑下型钢保留,能有效隔绝地下水的渗透,防止隧道结构薄弱部位渗漏水现象发生。通过对隧道基底进行满堂加固处理,有效增加了坑底地基承载能力,提高了开挖过程中的稳定性。

The total length of the tunnel from Qingliu Road to Qingdong Road is 853m in the lifting and rebuilding project of East Avenue.In order to achieve a low disturbance of the subway in the protected area while taking into account the construction quality,this paper summarizes the construction protection measures for open-cut tunnels in the protected area by analyzing the design drawings,the surrounding environment and the engineering geological conditions,which effectively solves the construction problems of open-cut tunnels in the protected area.By using SMW method piles and MJS piles to reinforce the tunnel near the variable section of the existing structure,retaining the section steel under the foundation pit of the closure wall,the seepage of underground water can be effectively isolated and the seepage of weak part of tunnel structure can be prevented.The full-hall reinforcement treatment of tunnel foundation effectively increases the bearing capacity of foundation at the bottom of pit and improves the stability during excavation.