复合地层下穿高铁超大矩形盾构隧道开挖面的极限支护力

Ultimate Support Force of Excavation Face of Super-Large Rectangular Shield Tunnel Crossing High-Speed Railway in Composite Stratum

为了保证超大矩形盾构隧道开挖面的稳定性,依托某超大矩形盾构隧道工程,采用理论分析、数值模拟和现场监测方法对复合地层下穿高铁超大矩形盾构隧道开挖面的极限支护力进行了研究,提出了复合地层下穿高铁超大矩形盾构隧道开挖面临界破坏模式,并基于极限平衡理论推导了极限支护力计算方法。数值模拟和现场监测结果表明:提出的极限支护力计算方法与数值模拟和现场监测的误差分别在10.40%~18.30%和11.19%~16.85%区间,说明极限支护力公式安全可靠,可应用至实际工程中。研究结果可为类似工程开挖面稳定性控制提供参考。

To ensure the face stability of the super-large rectangular shield tunnel,based on a super-large rectangular shield tunnel,the theoretical analysis,numerical simulation and field monitoring are used to study the ultimate support force of the super-large rectangular shield tunnel crossing the high-speed railway in the composite stratum.The critical failure mode of excavation surface of super-large rectangular shield tunnel crossing high-speed railway in a composite stratum is proposed,and the calculation method of ultimate support force is deduced based on the ultimate equilibrium theory.The results of numerical simulation and field monitoring show that the errors between the proposed ultimate support force calculation method and numerical simulation as well as the proposed ultimate support force calculation method and field monitoring are 10.40%–18.30%and 11.19%–16.85%,respectively.The formula of ultimate support force is safe and reliable,and can be applied to practical engineering.The research conclusion can provide a reference for the stability control of excavation face in similar projects.