A Limit Equilibrium Model For 3D Slope Analysis Based On Vector Sum Method And Application

The limit equilibrium theories for three dimensional (3D) slope stability analysis since 2001 was summarized in detail. According to the deficiencies of these methods (lack of equilibriums and excess simplification of geometic model of slope, etc.), some research were studied as following:(1) The concept of three lateral shear factors and three lateral shear distribution functions were presented to propose a a new general 3D slope limit equilibrium method, which fully made use of the three-axials force balances of each column and the three-axials total moment equilibriums. Combining with the definition of safety factor of Vector Sum Method, through the analysis and simplification of distribution functions and lateral shear factors, the Simplified Janbu-Vector Sum Analysis Method (J-V) was proposed for the application for engineering(2) The Expansion of Two Dimensional Slip Method (ETDS) was presented to search for the initial critical surface, utilizing the results of two-dimensional analysis extent to the 3D analysis. A simplified Three-Dimensional Monte Carlo random Approach (3 DMCA) was developed to increase efficiency of searching for the initial critical surface.(3) The Least Square Method simulating the sliding surface and the "in" and "out" safety factor concept were adopted to improve the accucy of calculation.(4) Two-dimensional strength reduction method and J-V analysis were applied for the comprehensive stability analysis of the LNG power plant. Some useful advices were provided for the design and construction.