Research On The Influence Of Vertical Underpass Construction Of Shield On Deformation Law Of Underground Comprehensive Pipe Corridor

As an important embodiment of a smart city,the underground comprehensive pipe corridor has well solved the urban shortcomings of the "zipper road".The obvious advantages of the underground comprehensive pipe corridor in urban construction and management have made it enter large-scale construction in China.With the large-scale construction of underground comprehensive pipe corridors,shield construction,as an important construction method of current underground engineering construction,will inevitably affect the existing underground comprehensive pipe corridors,and how to avoid the existing underground comprehensive pipe corridors.The occurrence of operational risks and disasters has become a major challenge in the construction of underground projects.In this paper,through the design of indoor model experiments and numerical simulation methods,under the condition that the shield vertically penetrates the underground comprehensive pipe corridor,the deformation law,failure characteristics and mechanical response mechanism of the existing underground comprehensive pipe corridor structure are investigated.In order to explore,the main results of this study are as follows:(1)Through the indoor model test,the deformation law of the underground comprehensive pipe corridor during the construction of the shield underpass is obtained: the overall combined deformation of the pipe corridor presents a flexible deformation characteristic,which meets the description of the peck formula,and its single pipe section presents a rigid deformation characteristic.The main deformations are overall settlement,longitudinal deflection,tilt,and relative torsion in cross section.(2)On the one hand,the numerical simulation method is used to verify the deformation law of the pipe corridor structure obtained by the indoor model experiment,and the results show the reliability of the data of the indoor model test;on the other hand,the mechanical response,The evolution mechanism is studied,mainly by analyzing the stress changes of the horizontal and vertical sections of the tunnel corridor and the contact surface when the shield excavation surface and the tunnel corridor structure are in different positions,and the deformation form of the tunnel corridor structure is explored from a mechanical perspective.(3)Combined with model test data and numerical simulation results,the main deformation and failure characteristics of the pipe corridor structure are summarized.The deformation failures are mainly longitudinal deflection failure,longitudinal and transverse shear failure,torsional failure in cross section,transverse warpage and bending damage.Based on the deformation failure form and the damage mechanism of the pipe corridor structure,combined with the existing engineering construction reinforcement measures,the pipe corridor deformation control measures are proposed from three aspects: reducing formation deformation,blocking deformation and deformation compensation.