Internal Stability Analysis And Optimum Design Of Reinforced Earth Structures Using Genetic Algorithm

Because of its good tensile and compressive properties,geosynthetics reinforced soil is widely used in subgrade,abutment,dam and other projects,and the most common is to use it to form retaining structures-reinforced soil structures(reinforced soil retaining wall and slope).In general,internal stability is an important basis for the design of reinforced soil structures.The engineering cost will directly affect its engineering application and promotion.Therefore,the important task in the field of reinforced soil structure research is to combine the internal stability research with the optimal design.Based on the mechanism of logaritymic spiral failure,the internal stability of the reinforced soil structure is studied in this paper,and then the seismic stability of the reinforced soil structure is analyzed by using the pseudo-dynamic method.Finally,combined with the results of stability research,the optimization design model of reinforced soil structure was established with the project cost as the objective function.In addition,the genetic algorithm is used to solve the tensile force and optimization design model of steel bars.The specific research contents are as follows:(1)Determine the value of the search main parameter about the genetic algorithm of the key slip surface of the reinforced soil structure,calculate the maximum reinforcement tension required by the reinforced soil structure in the ultimate state,and compare and analyze the calculation results of the method presented in this paper and the analytical method.(2)The internal stability mechanical models of the plane and concave reinforced soil structures under the ultimate state were established by comprehensively considering the mechanical properties of the filling,the geometrical profile parameters of the reinforced soil structures and the overburden loads,and the calculation formulas of the tensile force of the reinforced materials were deduced.Based on the influences of the internal friction angle of the filler,the cohesion of the filler,the inclination angle of the wall,the inclination angle of the overburden,the depth of the tensile crack and the upper load,the tensile force of the reinforcement for the plane and concave reinforced soil structures was compared and analyzed.(3)With the help of the pseudo-dynamic method,the mechanical model of the reinforced soil structure under static conditions is extended,and the internal stability mechanical model of the planar and concave reinforced soil structure under seismic conditions is established respectively.The differences between the proposed method and the pseudo-static method were compared and analyzed based on the effects of damping ratio,packing cohesion,internal friction angle and wall inclination angle.(4)Based on the research results of the internal stability of reinforced soil structure in this paper,the optimal design models of reinforced soil retaining wall and slope were established respectively,taking the engineering cost as the objective function and the design requirements of the stability of reinforced soil structure as the constraint conditions.Genetic algorithm is used to solve the model.Based on a specific example,the calculation results of the proposed method are compared with those of the methods in the literature.