Simulation analysis of seismic dynamic response of small interval tunnel in deep backfill area based on model test

Abstract

In order to reveal the seismic dynamic response law of small interval tunnel in soil rock backfill area, relying on the subway section tunnel project, a three-dimensional finite element model is established on the basis of model test to analyze the seismic dynamic response of tunnel lining structure and foundation pile. The results show that: 1) under the action of earthquake, the greater the peak acceleration of seismic wave , the stronger the stratum nonlinearity; 2) under the action of Kobe wave and Wolong wave, the bending moment of the left and right spandrels of the tunnel is the largest in the X direction, showing an “X” shape distribution as a whole; In the Y direction, the bending moment at the arch foot of tunnel lining is the largest, and the overall distribution shape is an inverted “V”; 3) under the action of Kobe wave and Wolong wave, the tensile stress and shear stress of the lining of the left and right tunnels are the largest at the left and right arch feet, showing an “X” shape distribution as a whole; 4) under the action of different peak Kobe wave and Wolong wave, the horizontal displacement of tunnel-pile structure gradually increases with the increase of height, and reaches the maximum at the top of lining arch.