Abstract:To improve the safety and stability of tunnels, a numerical simulation study was conducted on the deformation of the surrounding rock of deep-buried tunnels under earthquake. Taking a tunnel in a city as the object, we used FLAC software to build a three-dimensional dynamic model. Based on the physical and mechanical parameters and seismic load conditions, we used the relative displacement method to study the surrounding rock deformation characteristics, energy accumulation characteristics, and safety performance of a deep-buried tunnel under earthquake. The results show that the surrounding rock of the deep-buried tunnel is affected by the earthquake load, which results in the tendency for squeezing and elliptical deformation. When the deformation reaches maximum value, areas with a strain energy density higher than 2 350 J/m3 are concentrated in the tunnel wall on the left side of the surrounding rock and middle rock pillar; The safety factor of each monitoring point is asymmetric, and that of the lower corner area on the right side of the tunnel is lower than the value specified in the relevant national code. The calculated results are in good agreement with the actual measurement results.