软弱地层下穿高铁超大矩形顶管盾构隧道施工稳定性研究

A Study on Stability of Super-large Rectangular Pipe-jacking Shield Tunnel for High-speed Railway Underpassing Soft Ground

为保证超大矩形顶管盾构隧道近接下穿高速铁路施工稳定性,本文依托某火车站地下通道工程,建立软弱地层近接下穿高铁超大矩形顶管盾构隧道施工力学模型,结果表明:(1)埋深因子越大,地表沉降、轨道变形和管节收敛变形越大,管节安全系数越小;(2)黏聚力因子和内摩擦角因子越大,地表沉降、轨道变形和管节收敛越小,管节安全系数越大;(3)管节因子越大,地表沉降、轨道变形和管节收敛逐渐减小,管节安全系数增加;(4)软弱地层超大矩形顶管盾构隧道近接下穿高铁施工时埋深因子越小,黏聚力因子、内摩擦角因子和管节因子越大,其施工稳定性越好。研究成果可为类似工程提供参考。

In order to ensure the stability of super-large rectangular pipe-jacking shield tunnel near an underneath high-speed railway,the underground passage of a railway station was taken as a case for study in the paper,and a construction mechanics model of such a tunnel in soft ground was established,to study the impact of tunnel depth,stratum parameters,and element on surface settlement,track deformation,element convergence,and safety coefficient.The results show that:(1)The greater the depth is,the greater the surface settlement,track deformation,and element convergence deformation are,and the smaller the element safety factor is.(2)The greater the cohesion factor and internal friction angle factor are,the smaller the surface settlement,track deformation,and element convergence are,and the greater the element safety factor is.(3)The larger the element factor is,the smaller the surface settlement,track deformation,and element convergence are,and the safety factor of elements increases.(4)The smaller the depth is,the larger the cohesion factor,internal friction angle factor,and element factor are,and the better the construction stability is when the super-large rectangular pipe-jacking shield tunnel in soft ground is close to the construction of underpass high-speed railway.The findings may be used as reference for similar projects.