Abstract:
A large scale model test was carried out to study the dynamic response of the oblique metro tunnel in ground fissures area under vibration loads of train. The test results show that subway produces vibration propagation in all directions in the soil with different degree of attenuation while moving, and ground fissures have barrier action on the vibration. The vibration of the ground fissures near the tunnel beneath the soil is larger than that of the upper soil layer, and the vibration response of the arch bottom of the subway tunnel is stronger than that of the hance and the vault. Before ground fissure movements, the additional contact stress is larger between the bottom of the tunnel and the soil; While the declining of the hanging wall of ground fissures, the additional contact stress between the bottom of the footwall tunnel and the top of the hanging wall tunnel near ground fissures and the soil become larger. Before ground fissure movements, the additional strain caused by vibration excitation at both the top and bottom of the tunnel are smaller. While the declining of the hanging wall of ground fissures, the negative additional strain occurs at the top of the hanging wall tunnel and the bottom of the footwall tunnel, while the positive additional strain occurs at the top of footwall tunnel and the bottom of halling wall tunnel. The additional strain becomes larger when the hanging wall declines.