基于有限元强度折减法非均质边坡稳定性的数值研究

发布时间：2018-03-21 04:30

本文选题：强度折减法　切入点：非均质边坡　出处：《南昌航空大学》2016年硕士论文　论文类型：学位论文

【摘要】：边坡稳定性分析是边坡工程和边坡设计中最基本的问题。与传统的极限分析法、极限平衡法相比,有限元强度折减法最大的优势在于无需假定滑动面的形状和位置就可自动求得临界滑动面及相应的安全系数。有限元强度折减法具有数值分析方法和极限平衡法两者的优点,在计算边坡安全系数方面初见成效,但应用面还不够宽,特别是较少用于工程中最常见的非均质边坡。基于此,本文针对非均质边坡的稳定性,探讨基于有限元强度折减法的具体应用问题,主要内容和结论如下:(1)归纳总结强度折减法安全系数的几种定义,从理论上探讨各种定义与极限平衡法中安全系数的关系;(2)利用ANSYS对均质边坡建立计算模型,采用不同屈服准则进行弹塑性稳定分析求出安全系数,并将其与极限平衡法所得安全系数进行比较,探讨各个屈服准则的合理性和适用性,得到边坡稳定性问题分析中较适宜采用的屈服准则为D-P5准则。(3)基于ANSYS建立非均质边坡计算模型,对应三种不同判据求出相应的边坡安全系数,对比数值结果的合理性,分析各判据的适用性,并提出相应建议。对数值结果中位移监测点的选择和监测方式进行了细致的分析与讨论,得出采用坡顶作为监测点较为合理。(4)针对非均质边坡模型,分析了不同坡角下分别改变粘聚力c和内摩擦角φ时边坡的安全系数F,结果表明,边坡的安全系数与粘聚力和内摩擦角都呈正比关系。与均质边坡不同,非均质边坡不存在等效影响角θσ,即不存在粘聚力和内摩擦角对稳定性的影响程度相同的坡角。
[Abstract]:Slope stability analysis is the most basic problem in slope engineering and slope design. The greatest advantage of the finite element strength reduction method is that the critical sliding surface and the corresponding safety factor can be obtained automatically without assuming the shape and position of the sliding surface. The finite element strength reduction method has the advantages of both the numerical analysis method and the limit equilibrium method. The calculation of slope safety factor has achieved initial results, but the application area is not wide enough, especially for the most common non-homogeneous slope in engineering. Based on this, this paper aims at the stability of non-homogeneous slope. This paper discusses the concrete application of the strength reduction method based on the finite element method. The main contents and conclusions are as follows: (1) several definitions of the safety factor of the strength reduction method are summarized and summarized. The relationship between various definitions and the safety factor in the limit equilibrium method is discussed theoretically. The ANSYS is used to establish the calculation model of homogeneous slope, and the safety factor is obtained by using different yield criteria for elastic-plastic stability analysis. Compared with the safety factor obtained by the limit equilibrium method, the rationality and applicability of each yield criterion are discussed. The more suitable yield criterion for slope stability analysis is D-P5 criterion. (3) based on ANSYS, the calculation model of heterogeneous slope is established. The safety factor of slope is calculated according to three different criteria, and the rationality of numerical results is compared. The applicability of each criterion is analyzed, and corresponding suggestions are put forward. The selection and monitoring methods of displacement monitoring points in numerical results are analyzed and discussed in detail. It is concluded that it is more reasonable to use the top of slope as the monitoring point. The safety factor F of the slope is analyzed when the cohesion force c and the internal friction angle 蠁 are changed respectively at different slope angles. The results show that the safety factor of the slope is proportional to the cohesion force and the angle of internal friction, which is different from that of the homogeneous slope. There is no equivalent influence angle 胃蟽 in non-homogeneous slope, that is, there is no slope angle with the same influence on stability as cohesion and internal friction angle.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU43

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