Deformation and failure mechanism of deep-buried tunnel under the action of fault dislocation and application of nonlocal model in numerical simulation research

Fault dislocation leads to the deformation and failure of deep-buried tunnels, directly affecting the safety of human life and property. In this paper, a physical model test is performed to summarize the deformation and failure mechanism of a deep-buried tunnel subjected to fault dislocation by analyzing tunnel strain, contact pressure, and failure mode. The test is then simulated using a nonlocal model to verify its validity in simulating the response characteristics of tunnel deformation and failure under fault dislocation. The results show that: (1) The deep-buried tunnel undergoes deformation and failure under shear, bending, and compression combined. The shape of the tunnel model after the overall deformation is relatively similar to that of 'S'; (2) The nonlocal model can effectively reproduce the test results and resolve the mesh-dependent problem of numerical simulation results. The research results have guiding significance for the design and construction of deep-buried tunnels that pass through faults. These findings expand the numerical simulation methods for studying the response characteristics of tunnels to fault dislocation.