Study On The Limit Analysis Method Of The Cantilever Sheet Pile Wall Supporting Structure

With the development of urban construction, human demand for region space is more and more big, but because of non-renewable resources of land, so the development and utilization of the underground space has increasingly become the focus of attention of mankind, and therefore the geotechnical structure stability problems have become increasingly prominent. At present, due to the complexity of the soil-structure interaction, with the corresponding theoretical research obviously lags behind engineering practice. Therefore, the strengthening involving the geotechnical structure stability of soil-structure interaction is particularly important.The instability of the cantilever sheet pile with the methods of the laboratory model experiments, the numerical analysis and limit analysis is discussed. The PIV method, non-intrusive measuring system, is used for tracking the whole movement of sheet pile wall and the surrounding soil, during the process of excavation. And numerical analysis results is right in comparison with model test results. Finally, the collapse mechanism of cantilever sheet pile wall in the undrained cohesive soil with the numerical analysis and limit analysis is discussed.By the laboratory model experiments, the lateral displacement of the sheet pile wall and the settlement displacement of the support side is measured, the curve of displacement and excavation depth is drawn, and the displacement vector diagram on the support side by the particle image velocimetry is obtained; By the numerical simulation, the safety factor, shearing force and bending moment after each step excavation is got, and the curve of safety factor and excavation depth is made, the influence law of soil friction angle, undrained shear strength, soil heavy, water line and insertion ratio to safety factor is summarized. According to the plastic damage model in the cohesive soil, the analytical solution with the method of limit analysis upper bound is derived. Finally, according to the analytical solution, the curve of safety factor and each factor is made.