北京地铁4号线备用站台隧道工程富水砂卵石层注浆技术

Grouting Technology on Tunnel Project of Alternate Station of Beijing Metro Line 4 in Water-rich Sand and Cobble Stratum

由于地层条件千变万化,地铁暗挖中隧道穿越处于老河床含承压动水不均匀砂卵石中,拱部处于无粘结、自稳能力差的砂卵石层,易发生涌水涌砂,给开挖带来极大安全隐患,使得当前和后续施工的质量和安全保证难度加大。作为暗挖施工的超前注浆显然成为施工过程中防塌陷下沉的重要控制环节。本文以北京地铁4号线备用站台为例,详细介绍超前管棚及水平旋喷桩的打设、注浆材料的选取,以及注浆过程控制等。

Due to the ever-changing stratum conditions,tunnel passing through uneven sand and cobble stratum lies in the old riverbed with confined hydrodynamic pressure during the process of subway excavation,the arch is in unbonded,poor self-stabilizing sand and cobble stratum prone to gushing water and sand,which could bring great security risk to excavation and make the current and subsequent construction quality and safety assurance difficult. Advanced grouting,as one of the processes of excavation construction,is obviously proved to be the important control link for avoiding collapse and sinking during the construction process. This paper,taking alternate station of Beijing Metro Line 4 as an example,makes a detailed introduction of driving and setting of advanced pipe shed and horizontal rotary jet grouting pile,selection of grouting materials and grouting process control.