膨胀土路堑高边坡稳定性分析及支护参数优化研究

发布时间：2018-03-02 14:57

本文选题：膨胀土　切入点：路堑高边坡　出处：《南昌工程学院》2017年硕士论文　论文类型：学位论文

【摘要】：随着国家经济和交通运输业的发展,高速公路的建设也从城市向偏远山区发展,无疑会遇到很多路堑边坡的稳定性问题。膨胀土具有胀缩性、裂隙性、强度衰减等特点,导致膨胀土边坡比一般边坡更易产生滑坡。本文针对膨胀土特殊的工程特性,对膨胀土路堑边坡滑坡机理进行了分析,并以江西万宜高速公路的某一膨胀土路堑高边坡为工程背景,对锚杆框架梁加固膨胀土路堑边坡的稳定性进行了数值计算分析,还对框架梁支护参数进行了优化研究,同时对考虑降雨和裂隙耦合作用下的膨胀土边坡稳定性进行了研究。本文主要工作如下:1.膨胀土边坡滑坡机理和特点分析。通过总结国内外对膨胀土边坡的滑坡机理的研究,阐述了裂隙的产生和发展是影响膨胀土边坡滑坡的关键因素,归纳总结膨胀土边坡滑坡特点及各加固方案的适用性。2.锚杆框架梁加固土质边坡受力分析。基于界面软化滑动力学模型假定,建立锚杆受力变形阶段的位移、轴力的微分表达式,并通过数学推导获取方程解析解。按照建筑基础的方法考虑计算框架梁内力的3种计算模型,阐述了各种模型的基本理论及不足。3.工程边坡膨胀土力学参数试验。对万宜高速公路A2标段某膨胀土路堑边坡进行了现场原位取土,在实验室进行了膨胀土三轴剪切、三轴渗透等试验,得到了膨胀土相关的力学参数。4.锚杆框架梁加固膨胀土路堑边坡稳定性数值计算及支护参数优化研究。采用有限差分方法对锚杆框架梁加固膨胀土路堑多级边坡的稳定性进行了数值模拟分析,对锚杆框架梁支护参数(如锚杆间距、长度以及布设角度等)进行了优化研究,为工程设计提供了理论依据。5.降雨和裂隙耦合作用下膨胀土边坡稳定性影响分析。采用有限元分析(seep/w)与极限平衡分析(slope/w)相结合的方法,对降雨和裂隙耦合作用引起的膨胀土边坡渗流场变化与边坡稳定性进行了研究。在此基础上,对锚杆支护膨胀土路堑边坡的稳定性进行了评价,验证了锚杆支护膨胀土边坡的可靠性。
[Abstract]:With the development of national economy and transportation industry, the construction of freeway is also developing from city to remote mountain area, which will undoubtedly encounter many problems of stability of cutting slope. Expansive soil is characterized by dilatancy and shrinkage, fissure, strength attenuation, etc. In this paper, the landslide mechanism of expansive soil cutting slope is analyzed according to the special engineering characteristics of expansive soil. Taking a high expansive soil cutting slope of Wanyi Expressway in Jiangxi Province as the engineering background, the stability of expansive soil cutting slope strengthened by anchor frame beam is numerically calculated and analyzed, and the parameters of frame beam support are optimized. At the same time, the stability of expansive soil slope considering the coupling of rainfall and crack is studied. The main work of this paper is as follows: 1. The landslide mechanism and characteristics of expansive soil slope are analyzed, and the landslide mechanism of expansive soil slope at home and abroad is summarized. It is expounded that the occurrence and development of cracks are the key factors affecting the landslide of expansive soil slope. The characteristics of expansive soil slope landslide and the applicability of each reinforcement scheme are summarized. 2. The stress analysis of soil slope strengthened by anchor frame beam. Based on the assumption of dynamic model of interface softening and sliding, the displacement of anchor rod in deformation stage is established. The differential expression of axial force and the analytical solution of the equation are obtained by mathematical derivation. According to the method of building foundation, three kinds of calculation models for calculating internal force of frame beam are considered. The basic theory and deficiency of various models are expounded. 3. Test of expansive soil mechanical parameters of engineering slope. The in-situ sampling of expansive soil cutting slope in A 2 section of Wanyi Expressway is carried out, and triaxial shear of expansive soil is carried out in laboratory. Triaxial permeation test, The mechanical parameters related to expansive soil. 4. Numerical calculation of stability of expansive soil cutting slope strengthened with anchor frame beam and optimization of supporting parameters are obtained. Finite difference method is used to reinforce expansive soil cutting multi-stage slope with anchor frame beam. Numerical simulation analysis of the stability of the. In this paper, the support parameters (such as bolt spacing, length and placement angle) of bolting frame beam are optimized. The paper provides a theoretical basis for engineering design. 5. Stability analysis of expansive soil slope under the coupling of rainfall and fracture. The method of combining finite element analysis with limit equilibrium analysis is used to analyze the stability of expansive soil slope. The seepage field variation and slope stability of expansive soil slope caused by the coupling of rainfall and crack are studied. On this basis, the stability of expansive soil cutting slope supported by bolt is evaluated. The reliability of the expansive soil slope supported by bolt is verified.
【学位授予单位】：南昌工程学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.167

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