【作者】 方建瑞；

【导师】 朱合华； 蔡永昌；

【作者基本信息】 同济大学 ， 结构工程， 2007， 博士

【摘要】 对边坡稳定直接采用三维方法进行分析具有重要的理论和现实意义，本文对边坡稳定三维分析的基本方法做了比较系统的总结，并指出各种方法存在的问题，同时提出一种基于三维有限元应力场计算边坡安全系数与直接搜索临界滑裂面的新方法。该方法克服了三维极限平衡分析方法在理论上引入较多假设条件，且搜索临界滑裂面困难的问题；它直接采用三维有限元应力场，不同于三维有限元强度折减法基于虚拟荷载上得出的实用价值；同时异于沿用极限平衡理论的有限元法仍需要进行条柱划分，并事先假设滑裂面形状及位置的缺点。在这种方法中，临界滑裂面上的应力分布直接使用三维有限元计算的应力结果，并且直接利用三维有限元的单元体网格面作为滑移面搜索网格面，鉴于有限元单元体网格和图的直观相似性，可以把网格抽象成图，通过引用动态规划中最优化思想搜索临界滑裂面。本文方法不需要假定三维滑裂面的形状与位置，只需通过构筑滑动模式，搜索出来的临界滑裂面是由单元体的网格面以边相互连接而成的一个空间曲面。本文通过对三维有限元直接搜索法的研究，并将其应用于隧道边坡的稳定性分析中，主要的研究内容有：1、研究了动态规划原理及其在三维边坡稳定性分析中的应用，引入图论概念，构筑出一种边坡三维滑裂面的滑动模式，借助一个包含安全系数的辅助函数并通过动态搜索求得临界滑裂面与最小安全系数；2、采用C++程序设计语言，编制出边坡三维稳定性分析以及直接搜索法的程序，通过一些算例的对比分析，验证本文方法的适用性，并讨论了三维分析中的一些影响因素。3、结合隧道边坡的不同实际情况，考虑施工开挖过程、衬砌结构及降雨渗流等方面的因素，利用本文方法研究对其稳定性的影响和规律，并提出处理措施。更多还原

【Abstract】 It is very important academic and practical significance to use 3D method directly in the slope stability analysis. Systemic summary to the essential method of 3D slope stability analysis and their problems are presented in this paper. Simultaneously a new method to calculate the safety factor and search critical slip surface based on 3D FEM’s stress result is given in this paper too. This method overcome the problems of many supposition conditions in theory and difficulty in searching critical slip surface in 3D limiting equilibrium analysis; It uses the 3D FEM’s stress field directly, differs from the practical value of 3D FEM strength reduction method used hypothesized load, and differs from the characteristic of the FEM with limiting equilibrium theory still to need to divide the columniation, and suppose the critical slip surface in advance. In this method, stresses acting along the critical slip surface are computed using 3D FEM analysis, moreover the 3D FEM mesh is used directly as the searching grid. In view of the fact that it is intuitionistic similarity between a FEM mesh and a graph, the mesh may be abstract to a graph, and the optimized thought in dynamic programming may be used to search. This method does not need to suppose the shape and position of 3D critical slip surface, only through the construction of glide pattern, and the searched critical slip surface is a space surface which connects mutually by the grid surface.Through the research of direct search method based on 3D FEM, and its application for the tunnel slope stability analysis, the objectives of this work in this paper are as follows:1. The dynamic programming as well as its application for 3D side slope stability analysis is studied. With the introduction of graph theory concept, one kind of glide pattern of 3D slope is constructed, and the critical slip surface with smallest safety factor is searched with the aid of one auxiliary function including safety factor;2. Using the C++ programming language, the 3D slope stability analysis and the direct search procedure is established, and this method is testified applicably by some contrast analysis, also some influence factor in analysis is discussed;3. Integrated with the different actual situation in tunnel slope, considered its excavation, timbering and rain infiltration, its stability influence and rule is researched used this method, also some processing measure is proposed.更多还原