Dynamic Centrifuge Test and Numerical Modelling of the Seismic Response of the Tunnel in Cohesive Soil Foundation

Abstract

Few studies have been published on the dynamic centrifuge model test of cohesive soil under earthquake action. The seismic response of cohesive soil foundation and tunnel was studied by the centrifuge experiment and numerical modelling. Through a comparison of the acceleration results of tunnel and cohesive soil foundation and the pore pressure and displacement of cohesive soil foundation, the influence of tunnel on cohesive soil foundation is discussed. The weak position of the tunnel under earthquake is predicted by effective numerical modelling. The results show that: (1) Under the Parkfield seismic wave, the natural frequency of the cohesive soil foundation with the tunnel is about 0.3 Hz, which is the most clear for the amplification of the low frequency component and the amplification of the seismic acceleration from bottom to top; (2) The acceleration response of the tunnel itself is small, and the effect of seismic wave on the surrounding soil is weakened due to the existence of tunnels; (3) The maximum bending moment and shear force appear at the corner of the rectangular tunnel, and the maximum axial force appears at the top of the rectangular tunnel; (4) The lateral displacement of the surface soil is the largest, and the pore pressure reduction in the middle soil is the largest compared with other soil layers. The existence of tunnels weakens the liquefaction potential of the surrounding soil.