基于有限元强度折减法的抗滑桩—边坡体系稳定性研究

发布时间：2018-04-25 12:09

本文选题：有限元强度折减法 + 抗滑桩　；参考：《大连理工大学》2013年硕士论文

【摘要】：边坡稳定性评价和滑坡治理工程问题具有悠久的研究历史,但是由于其复杂性,边坡相关问题目前仍是学术人员和工程人员的热点话题。抗滑桩是目前最常用的边坡加固措施之一,但是有关抗滑桩的理论和计算方法却不够成熟,仍有部分问题没形成统一而明确的认识。为探究抗滑桩对边坡稳定性和破坏模式的影响以及抗滑桩自身的位移和内力反应,深入揭示抗滑桩-岩土体-边坡之间的相互作用关系,为理论研究和工程实践提供可信的参考,本文采用经典数值算例和实际工程案例,以有限元强度折减法为手段,开展了如下研究工作：采用多个算例,讨论简单均质边坡中无量纲参数λ=c/(γHtanφ)与边坡的安全系数和临界滑动面之间的关系,利用这个重要的规律,建立了基于强度折减有限元法的简单均质边坡强度参数反演分析方法。对某工程中的高填方边坡进行拟静力稳定性分析,探讨不同的地基处理方式(碎石桩和强夯置换)对边坡稳定性和破坏模式的影响。采用单排抗滑桩加固边坡,深入分析了加固效果和破坏模式、桩身的位移和内力反应以及沿着桩身的土压力分布情况；考虑四种不同的桩头约束情况(自由、不旋转、铰接和固定),分析其稳定性安全系数和临界滑动面的差异,探讨桩的变形和受力形式及峰值大小,并从沿着桩身的土压力分布情况来分析其原因；改变桩间距分别进行计算分析得到了单排桩加固边坡的安全系数的上界和下界,并分析了桩间距对桩间土拱效应形成的影响；对桩的不同加固位置进行模拟分析,得到了单排桩的最佳加固位置。采用双排抗滑桩加固边坡,基于等效桩架的概念提出了同单排桩等效的三种双排桩布桩形式(常规双排桩、错列双排桩和等效错列双排桩),并在不同的土体强度参数下从安全系数、桩身内力反应和土拱效应等方面讨论了最佳布桩形式的问题；同单排桩一样考虑了桩头约束效应对双排桩加固边坡的影响,并对比了前排桩和后排桩的桩身反应的差异,验证了阴影效应的存在；改变排距建模计算,分析了边坡的安全系数和桩身的内力反应,探讨排距对阴影效应的影响；选取不同的排距,考虑双排桩的位置对加固效果和桩身内力反应的影响,同时分析了特殊情况(S/D=1)下的边坡破坏模式受桩位的影响,从而探讨双排桩的最佳桩位问题。以大连岔鞍滑坡为工程实例,分析了开挖削坡对边坡稳定性和破坏模式的影响；地下水会导致滑带土强度参数的降低,探讨了地下水水位的变化对边坡整体稳定性和局部路堤边坡稳定性及破坏模式的影响；采用单排桩加固于边坡的中下部,分析了桩头自由和铰接两种约束条件下的加固效果和临界破坏面及桩身内力反应情况。
[Abstract]:Slope stability evaluation and landslide treatment engineering have a long history of research, but because of its complexity, slope related problems are still a hot topic for academicians and engineers. Anti-slide pile is one of the most commonly used slope reinforcement measures at present, but the theory and calculation method of anti-slide pile are not mature enough, there are still some problems have not formed a unified and clear understanding. In order to explore the influence of anti-slide pile on slope stability and failure mode, and the displacement and internal force response of anti-slide pile, the interaction between anti-slide pile and rock-soil-slope is revealed. For theoretical research and engineering practice to provide a credible reference, this paper uses classical numerical examples and practical engineering cases, using the finite element strength reduction method as the means, carried out the following research work: The relationship between the dimensionless parameter 位 Htan 蠁 (纬 Htan 蠁) and the safety factor and critical sliding surface of a simple homogeneous slope is discussed in this paper. A simple inversion analysis method for strength parameters of homogeneous slope based on strength reduction finite element method is established. The pseudostatic stability analysis of high fill slope in a certain project is carried out, and the influence of different foundation treatment methods (gravel pile and dynamic tamping replacement) on slope stability and failure mode is discussed. The single row anti-slide pile is used to reinforce the slope. The reinforcement effect and failure mode, the displacement and internal force response of the pile body and the distribution of the earth pressure along the pile body are analyzed in depth, and four different kinds of pile head constraints (free, non-rotating) are considered. The difference between the safety factor of stability and the critical sliding surface is analyzed, and the deformation, stress form and peak value of the pile are discussed, and the reasons are analyzed from the distribution of earth pressure along the pile body. The upper and lower boundaries of safety factor of single row pile reinforced slope are obtained by changing pile spacing, and the influence of pile spacing on the formation of soil arch effect between piles is analyzed, and the different reinforcement positions of piles are simulated and analyzed. The best reinforcement position of single row pile is obtained. Based on the concept of equivalent pile frame, three types of double-row piles (conventional double-row piles) are proposed for slope reinforcement with double-row anti-slide piles. Staggered double-row piles and equivalent staggered double-row piles are used to discuss the optimal layout of piles under different soil strength parameters, such as safety factor, pile internal force response and soil arch effect. Like single row pile, the influence of pile head constraint effect on reinforcement slope of double row pile is considered, and the difference of pile body response between front row pile and rear row pile is compared, the existence of shadow effect is verified, and the modeling calculation of changing row distance is made. The safety factor of the slope and the internal force response of the pile body are analyzed, and the influence of the row distance on the shadow effect is discussed, and the influence of the position of the double row pile on the reinforcement effect and the internal force response of the pile body is considered. At the same time, the influence of pile position on the failure mode of slope under special condition S / D ~ (1) is analyzed, and the optimum pile position of double row pile is discussed. The influence of excavation and slope cutting on the slope stability and failure mode is analyzed with the example of Dalian Chayan landslide, and the ground water will lead to the decrease of soil strength parameters in the slip zone. The influence of the change of groundwater level on the overall stability of the slope and the stability and failure mode of the local embankment slope is discussed, and the single row pile is used to reinforce the middle and lower part of the slope. The reinforcement effect and the reaction of the critical failure surface and the internal force of the pile body under the free and hinged conditions of pile head are analyzed.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU43

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