Analysis of Nonlinear Seismic Response and Stability for Tunnel Portal Slope

The nonlinear seismic response of transverse slope at secund tunnel portal is first studied with dynamic finite element method under conditions of horizontal, vertical and both horizontal and vertical input, and then the dynamic safety factors of the most dangerous slide face which vary with time are researched after adding the field of static stress. For the purpose of dynamic stability evaluation, the total average dynamic safety factor and the permanent displacement are bring forward and used in this paper. At last, the model of dynamic response analysis and stability evaluation is built for transverse slope at secund tunnel portal.