Analytical method of critical slip surface for soil slope with considering vertical seismic action effect and its application

Large amounts of investigation and research show that the vertical motion has a nonnegligible effect on the stability of soil slope. Based on the theory of limit equilibrium, this thesis satisfies the criteria of stress and kinematics under seismic with the aid of mathematical analytical method, and in accord with the geometrical compatibility condition of the deformation of slope. By solving the nonlinear equations, the acceptable minimum critical acceleration and critical slip surface are obtained. Finally, the mathematical expressions of determining the critical slip surface and the stability of slope are derived, which consider the effect of vertical earthquake. A numerical interface was also implemented for operation. Based on OpenSees, SlopeSAR, three-dimensional finite element software is independently developed and can conduct the seismic response and stability analysis of slope. The validity of this analytical method is verified by the finite element software. In addition, the effect of the vertical seismic action on soil slope was discussed under conditions of homogeneous slope, non-homogeneous slope, and homogeneous slope considered with pore pressure. The result shows that the vertical seismic action magnified the area and depth of the critical slip surface for soil slope significantly. This method could provide a new way for the stability analysis and determination of critical slip surface of the embankment slope in a mountainous area under strong earthquakes.