【作者】 吴坤铭；

【导师】 王建国；

【作者基本信息】 合肥工业大学 ， 工程力学， 2011， 博士

【摘要】 科学评价边坡稳定性、合理设计边坡抗滑桩加固工程已成为我国基础设施建设中的一个热点和难点问题。本文在分析评价现有的边坡稳定性分析方法的基础上,将智能响应面法应用于边坡稳定性分析中,结合蒙特卡罗模拟法对边坡可靠性进行科学评价和预报；抗滑桩作为一种有效的支挡工程措施已在边坡加固工程中得到了广泛应用,然而,其理论研究却滞后于工程应用,因此本文对抗滑桩设计计算方法展开研究,以优化工程设计。主要研究成果与结论如下：(1)基于可靠度敏感性的智能响应面法分析边坡可靠度：针对边坡工程中的非线性功能函数及非线性计算量大的问题,研究边坡可靠度敏感性,提出参数的相对敏感性分析方法,并基于可靠度敏感性分析提出两种智能响应面法分析边坡稳定性。研究表明：智能响应面法分析边坡稳定性是准确的且具有较高的计算效率,并可以有效解决传统响应面法可靠度计算不收敛问题；且两种智能响应面法计算结果几乎相同,可以互为验证,确保计算结果的准确性。(2)对常用的几种滑坡推力计算方法进行系统改进,改进后的滑坡推力计算方法概念清晰、应用方便。(3)系统推导抗滑桩内力分析计算的悬臂桩法的计算公式；建立抗滑桩内力计算的弹塑性有限元模型,系统推导给出非线性有限元方程组的求解方法,并根据迭代算法编制了相应的计算程序。研究表明：有限元法在做桩身内力计算时无须对滑坡推力分布作任何假定,可以充分考虑岩土材料的非线性力学特征、复杂的几何边界条件等,其计算结果较符合工程实际。(4)建立较为合理的桩间距计算模型；基于强度折减得出相应的桩间距计算公式,以考虑边坡工程等级及其他相关影响因素；在桩间距的计算模型和计算方法的基础上,建立桩间距的极限状态方程,分析岩土体的物理力学性质参数的变异性对抗滑桩间距可靠度的影响。研究表明：岩土体参数变异性对抗滑桩间距可靠度有显著的影响,因此,在确定抗滑桩间距时应考虑参数变异性的影响。(5)基于可靠性分析研究刚性抗滑桩锚固深度：建立锚固深度的可靠性分析模型,基于强度折减有限元法进行可靠度分析。研究表明：可靠指标的选取应考虑边坡工程等级；抗滑桩锚固深度计算参数应视为随机变量,计算参数的变异性对抗滑桩锚固深度可靠指标有显著的影响,在抗滑桩设计中不可忽视。(6)本文提出位移迭代有限元法,分析桩-土相互作用的动态变形协调过程,建立二维平面应变位移迭代有限元模型,对抗滑桩的内力及位移进行计算以进行抗滑桩设计；对影响位移迭代有限元模型计算结果的主要设计参数进行了敏感性分析,为桩身结构设计的优化提供了依据。(7)基于强度折减法设计边坡抗滑桩加固工程。采用强度折减有限元法对抗滑桩最佳桩位设置进行研究,研究表明：最佳桩位介于边坡中部和未加固边坡临界滑面中部之间且更接近于边坡中部。采用强度折减的位移迭代有限元法对加固后边坡的可靠性进行分析,以目标可靠度为控制指标逐步调整桩长,使加固后边坡的整体可靠度满足设计要求。更多还原

【Abstract】 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.更多还原