Geotechnical Stability Analysis Based On Discontinuity Layout Optimization And Non-Associatied Plasiticity

Geotechnical stability analysis methods mainly include limit equilibrium method,limit analysis method,finite element method and slip line method.In this paper,a new geotechnical stability analysis method based on energy principle,that is,Discontinuity Layout Optimization(DLO)method,is used to carry out geotechnical stability analysis and research.This method establishes a series of discontinuities(segments)in the solution domain of the rock and soil body,solves the work and energy loss of each discontinuity,and establishes an energy optimization equation based on the law of energy conservation.The failure mode of the geotechnical model is the mode that minimizes the total energy loss of the system.The main research contents and conclusions of this article are as follows:(1)The principle of discontinuity layout optimization method is introduced,emphasizing that this method is a limit analysis upper limit method.Based on the principle of discontinuity layout optimization,the corresponding algorithm was developed and the PYTHON program was compiled.Through specific calculation examples,the implementation steps of the discontinuity layout optimization method are introduced,and the specific implementation flow of the discontinuity layout optimization algorithm is given.(2)The discontinuity layout optimization method is applied to several typical geotechnical stability problems,including retaining walls,slopes,and foundations.For the retaining wall problem,the results of self-developed discontinuity layout optimization were compared with the results given in the references;for the stability of the slope problem,the slopes under homogeneous and non-homogeneous conditions were separately tested,and the results of the finite element program are compared with the results of the self-developed discontinuity layout optimization;for the problem of foundation bearing capacity,the theoretical solution of the Terzaghi formula is compared with the results of the self-developed discontinuity layout optimization.At the same time,the applicability of the discontinuity layout optimization method in geotechnical engineering problems was tested.(3)Apply the Davis formula to the discontinuity layout optimization method,so that the discontinuity layout optimization method can be used for the stability analysis of nonassociated plastic geotechnical model.The results of slope stability analysis in several cases without applying Davis formula,using original Davis formula and applying modified Davis formula were compared.The results show that the stability analysis results obtained by applying Davis formula and Davis formula are quite different.Therefore,it is very necessary to consider the non-associated plasticity in the stability analysis of rock and soil;When the degree of correlation is large,the calculation result of the modified Davis formula is more reasonable than the calculation result of the original Davis formula.