The invention discloses a tunnel two-parameter safety evaluation index construction method based on
dislocation and strong earthquake
coupling, and belongs to the technical field of
tunnel safety evaluation. The method comprises the steps that tunnel characteristic parameters and stratum rock-soil mechanical characteristic parameters are obtained, the fault
dislocation size is determined, and seismic
waves conforming to a standard spectrum are selected; establishing a multi-feature coupled nonlinear dynamic finite element numerical analysis model; on the basis of the fault
dislocation size and the selected
seismic wave, the nonlinear dynamic finite element numerical analysis model is adopted to calculate an incremental dynamic
time history, and a dynamic response curve of the tunnel lining structure under the action of multiple disasters is obtained; establishing a tunnel two-parameter
safety index function considering the
coupling effect based on the tunnel radial convergence rate and the plastic strain; and determining an index damage state and threshold division based on the tunnel two-parameter
safety index function and the lining response-structure performance curve, and taking the index damage state and threshold division as a tunnel two-parameter safety evaluation index.