软弱地层超大矩形顶管盾构隧道开挖面稳定性研究

Study on Stability of Excavation Face of Super-large Rectangular Pipe-jacking Shield Tunnel in Soft Ground

为保证超大矩形顶管盾构隧道开挖面稳定,本文以某超大矩形顶管盾构隧道工程为背景,建立了软弱地层超大矩形顶管盾构隧道模型,研究了不同内摩擦角因子、黏聚力因子、埋深因子时开挖面位移和支护应力差率曲线,结果表明:(1)埋深因子越大,相同支护应力差率m下矩形顶管盾构隧道开挖面位移越大,开挖面主动破坏时m越小,被动破坏时m越大;(2)黏聚力因子越大,相同m下矩形顶管盾构开挖面位移越小,开挖面主动破坏时m越小,被动破坏时m越大;(3)内摩擦因子越大,相同m下矩形顶管盾构开挖面位移越小,开挖面主动破坏时差率m越小,被动破坏时m越大。研究结论可为类似工程提供参考。

In order to ensure the stability of the excavation face of the super-large rectangular pipe-jacking shield tunnel,a super-large rectangular pipe-jacking shield tunnel model in soft ground is established in this paper based on a case study of a super-large rectangular pipe-jacking shield tunnel project to study the displacement and support stress difference curves of the excavation face at different internal friction angle factors,cohesion factors,and buried depth factors. The results show that:(1)The greater the burial depth factor,the greater the displacement of the excavation face of the rectangular pipe-jacking shield tunnel under the same support stress difference rate m,and the smaller the m in case of active failure of the excavation face,the greater the m in case of passive failure.(2)The greater the cohesion factor,the smaller the displacement of the shield excavation face of rectangular pipe jacking at the same m,and the smaller the m in case of active failure of the excavation face,the greater the m in case of passive failure.(3)The larger the internal friction factor,the smaller the displacement of the excavation face of the rectangular pipe jacking shield at the same m,the smaller the difference rate of active failure m of the excavation face,and the larger the difference rate of passive failure m. The research results may be used for reference by similar projects.