The unprecedented rate of metro construction has led to a highly complex network of metro lines.Tunnels are being overlapped to an ever-increasing degree.This paper investigates the deformation response of double-track overlapped tunnels in Tianjin,China using finite element analysis(FEA)and field monitoring,considering the attributes of different tunneling forms.With respect to the upper tunneling,the results of the FEA and field monitoring showed that the maximum vertical displacements of the ground surface during the tail passage were 2.06 mm,2.25 mm and 2.39 mm obtained by the FEA,field monitoring and Peck calculation,respectively;the heaves on the vertical displacement curve were observed at 8 m(1.25D,where D is the diameter of the tunnel)away from the center of the tunnel and the curve at both sides was asymmetrical.Furthermore,the crown and bottom produce approximately 0.38 mm and 1.26 mm of contraction,respectively.The results of the FEA of the upper and lower sections demonstrated that the tunneling form has an obvious influence on the deformation response of the double-track overlapped tunnel.Compared with the upper tunneling,the lower tunneling exerted significantly less influence on the deformation response,which manifested as a smaller displacement of the strata and deformation of the existing tunnel.The results of this study on overlapped tunnels can provide a reference for similar projects in the future.

Yao Hu;Huayang Lei;Gang Zheng;Liang Shi;Tianqi Zhang;Zhichao Shen;Rui Jia

School of Civil Engineering,Tianjin University,Tianjin,300350,China;Department of Civil and Environmental Engineering,National University of Singapore,117576,Singapore;Key Laboratory of Coast Civil Structure Safety(Tianjin University),Ministry of Education,Tianjin,300350,China;Key Laboratory of Earthquake Engineering Simulation and Seismic Resilience of China Earthquake Administration(Tianjin University),Tianjin,300350,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety(Tianjin University),Tianjin,300350,China

岩石力学与岩土工程学报（英文版）

[1]Yao Hu;Huayang Lei;Gang Zheng;Liang Shi;Tianqi Zhang;Zhichao Shen;Rui Jia-.Assessing the deformation response of double-track overlapped tunnels using numerical simulation and field monitoring)[J].岩石力学与岩土工程学报（英文版）,2022(02):436-447

heaves

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