The Reliability Analysis Of Slope And Their Reinforced With Anti-slide Piles

Scientific evaluation of slope stability and rational design engineering slope reinforced with piles becomes a hot and difficult topic in infrastructure construction of our country. Based on the review of the analysis method of slope stability, this article uses intelligent response surface method in the analysis of slope stability, combines with Monte Carlo simulation to be scientific evaluation and prediction of the slope reliability; the technique of anti-sliding pile is an effective measure in slope reinforcement, which has a wide application in the field, however studies on theory of these structure are delayed greatly than their applications, therefore, the design and calculation method of anti-sliding pile is studied in this thesis, which optimize engineering design. Main achievements and conclusions are as follows.(1) Research on slope reliability based on intelligent response surface method of reliability sensitivity:a reliability analysis of slope stability using intelligent response surface method is presented in this paper, which based on relative sensitivity analysis of the structural reliability. It is especially useful in such reliability analysis problems as slope stability whose performance functions are implicit and nonlinear problems have large amount of calculations, the results show that:the method of slope stability analysis is accurate and has higher efficiency, and can effectively resolve the traditional response surface method for reliability analysis of non-convergence problem; two kinds of intelligent response surface method are almost the same results, and can verify each other to ensure the accuracy of the results.(2) The commonly used calculation method of landslide thrust are improved, the improved method of landslide thrust which the concept is clear and is convenient to application.(3) The calculation formulas of cantilever-pile method is derived to analyze internal forces of rigid anti-sliding piles; a elastic-plastic finite element model with analyzing internal forces of anti-sliding pile is established, derivation gives the nonlinear finite element method for solving equations, the calculation program is desigend which based on iterative algorithm. The results show that:the finite element method in calculating internal forces of the pile do not make any assumption on the distribution of landslide thrust, which can fully consider the nonlinear mechanical characteristics of rock materials, complex geometry boundary conditions, etc, which calculation results consistent with engineering practice.(4) Considering arch effect between adjacent anti-slide piles the rational model for pile spacing is established; based on strength reduction, the calculation formulas for determining the anti-sliding pile spacing are proposed with consideration of the slope project classification and other factors, etc; establish the limit state equation of the pile spacing which based on the pile spacing model and calculation method, to analyze variability of the physical and mechanical properties of rock and soil parameters impact on the reliability of sliding pile spacing. The results show that:the parameter variability has a significant impact on the reliability of sliding pile spacing, therefore, when determining pile spacing, should be considered parameter variability.(5) Determination of anchoring depth for rigid anti-slide piles based on reliability analysis:the reliability analysis model for calculating the anchoring depth is established, the strength reduction finite element method is intruduced into this model to analyze reliability. The results show that:the classification of a slope project should be considered in selecting the reliability index; the calculated parameters are regarded as random variables, the parameter variability has a significant impact on the anchorage depth of anti-slide piles, therefore, the design of the pile can not be ignored the variability of parameters.(6) The displacement iterative finite element method which is to analyze dynamic deformation of the interaction process of the pile-soil is presented in this paper, two-dimensional plane strain finite element model of the displacement iteration is established, which is to calculate the internal forces and displacements of the pile for pile design; to analyze sensitivity of the main design parameters which affect the displacement iterative finite element model results, so as to provide the basis for design optimization of pile structure.(7) Based on strength reduction design for slope reinforced. Studing on optimization of the pile position based on strength reduction finite element method, the results show that:the exact optimized pile location lies between the middle of the slope and the middle of the critical slip surface of the slope with no pile, but it is much closer to the middle of the slope. To analyze the reliability of slope reinforced based on the method of strength reduction theory with displacement iterative finite element method, the target reliability as control index to guide the design for the anchoring depth of anti-slide, so that the overall reliability of slope reinforced to meet the design requirements.