Research On Upper Bound Method Of Plastic Limit Analysis For Rock Slope Contain With Rock Bridges

With the acceleration of China’s modernization process,the analysis of slope stability is more and more important in transportation engineering,water conservancy and Hydropower Engineering,energy engineering and other important projects,especially the stability of rock slope.The research topic of this paper is derived from the National Natural Science Foundation of China:the plastic limit analysis method for the toppling failure of layered rock slope(51564026),take the rock slopes contain with rock bridges as the research object,the ultimate bearing capacity of rock bridge is studied by the upper bound method of limit analysis,and the main research contents are as follows:(1)The significance of the research on the stability of rock slope contain with rock bridges is expounded.The analysis method of slope stability,the development and research status of plastic limit analysis method are introduced and summarized.(2)The basic theory and limit state of the plastic limit analysis method,and the proof and inference of theorem of the plastic limit analysis upper bound method are introduced,mechanical property,failure principle,development and research status of the rock bridges.(3)A new method for analyzing the stability of rock slopes contain with rock bridges is present,that is the upper method of plastic limit analysis for rock slopes contain with rock bridges based on the rigid block element.Use the rigid block element to usimulate the slope,combines with the plastic limit analysis upper bound method,the block element discretization technique and the non-liner mathematically programing,and build the non-liner mathematically programming which is used to calculate the overload ecofficient and the strength resever ecofficient.Then this method is used to calculate three examples of the rock slope contain with rock bridges,and comparing the results with those calculated by the rigid body limit equilibrium method and the finite difference method.(4)A new method for analyzing the stability of rock slopes contain with rock bridges is present,that is the upper method of plastic limit analysis for rock slopes contain with rock bridges based on the composite element method.The rock slope containing rock bridges are simulated by composite element method,and combining with the plastic limit analysis upper bound method,the block element discretization technique,the finite element discretization technique and the liner mathematically programming,then build the liner mathematically programming model that used to calculate the ultimate load or minimum factors coefficient is established,and use the Interior point algorithm to solve this problem.At last,the calculation and analyzing of two rock slope cases have been done,and compare the results with the results of other methods,which shows the proposed method is correct.(5)The research contents of this paper are summarized and the further research of this method is prospected.