Influence of Metro Shield Left/Right Line Tunnel Parallel Under-passing on the Defor-mation and Stress of Existing Open-cut Highway Tunnel under Deformation Joint Working Condition

Abstract

Objective To ensure the successful implementation of metro shield tunnel parallel under-passing through the existing open-cut highway tunnel project under deformation joint condition, it is necessary to analyze the deformation situation and stress characteristics of the mentioned highway tunnel under this working condition. Method A refined model of Jinan Rail Transit Line S2 left/right shield tunnel parallel under-passing of the existing open-cut highway tunnel in Jiluo Road Yellow River Tunnel project is established. The z-direction(vertical) settlement, x-direction (horizontal) displacement, and stress change of this highway tunnel structure bottom plate are analyzed. Through establishing two working conditions with and without deformation joint, changes of the z-direction settlement and x-direction displacement of the mea-sured line are compared. By selecting No.2 deformation joint in the project, the settlement difference and stress state development history on both sides of No.2 deformation joint are further analyzed. Result & Conclusion Compared to the working condition without deformation joint, that with deformation joint reduces the structural integrity of existing open-cut highway tunnels and changes its deformation and force characteristics. Deformation joints are always subject to tensile and shear stresses. Under deformation joint working condition, settlement on both sides of the deformation joint shows significant changes with the tunneling of metro shield, and reaches its maximum value when the tunneling is directly beneath the deformation joint.

Keywords

• metro shield tunnel
• deformation joint
• tunnel under-passing
• existing open-cut highway tunnel
• structural deformation
• structural stress