Sliding Surface Search Model Of Non-limit State Stress Field Slope And Its Stability Analysis

Slope stability has been a hot issue in geotechnical engineering for a long time.However,some major slope instability still occurs frequently while fruitful results have been achieved.Behind these accidents,there are many uncertain internal and external reasons,and some new problems emerge endlessly.Existing slope stability analysis methods,such as limit equilibrium method and finite element strength reduction method,are based on the limit state of the slope,which makes these methods have certain assumptions.However,with the continuous development of geotechnical slope reinforcement technology,the slope is often in a non-limiting state during the construction phase of the slope reinforcement and long-term use.In this state,the control of slope deformation and stability is often the focus of engineering safety evaluation,which is not available in traditional methods.Therefore,this paper proposes a model based on the non-limiting state stress field slope slip surface,and studies the stability of the slope under different conditions.Firstly,the author summarizes and analyses the current research status and basic theories and methods of slope stability,and puts forward the deficiencies and development trends of current research.Secondly,based on the finite element stress field in the non-limit state,a sliding surface search grid with a square-format discrete stress field is proposed.By establishing the geometric relationship between the search grid and the finite element mesh,the potential dangerous elements are identified by the stress state in the search grid in turn,so that the potential sliding surface of the slope under the non-limit state can be determined.The specific steps are as follows:(1)Using MIDAS-GTS to establish a numerical calculation model,and the model information and stress field data are obtained through calculation.(2)According to the geometric size of the finite element model,n strip meshes are created in two-dimensional coordinate system.(3)Establish the geometric relationship between the unit and the grid.By evaluating the stress state,the potential damage element in any sub-grid is searched,and the corresponding element coordinates and stress state are obtained.(4)These elements and their coordinates are used to generate curves,that is,the potential slip surface is determined in the non-limit state,and the safety factor is solved.Thirdly,the model is established with reference to the international classic slope example.The method proposed in this paper is compared with the existing methods to verify the rationality and advantages of the method.Finally,taking the example of slope engineering as the object,the stability of soil nailing wall slope support and pile-anchor slope support are analyzed respectively by the method proposed in this paper.The results show that the method of stability analysis based on stress state is suitable for the evaluation and analysis of slope stability under non-limit state.The calculation results are reasonable and have potential application value.The method and research results established in this paper have good scientific significance and reference value for slope stability deformation control and safety evaluation research.