数值流形法的改进及其在土石坝分析中的应用

发布时间：2018-03-04 23:26

本文选题：数值流形法　切入点：土石坝工程　出处：《大连理工大学》2014年博士论文　论文类型：学位论文

【摘要】：近年来大型高土石坝的建设,特别是在强地震区建设高土石坝日益增多,因而对土石坝采用更加精确合理的计算方法不但能够发现已建工程中存在的安全隐患,还能给将要建设的大坝提供更精确的设计依据,使大坝的建设更加合理,安全。数值流形法是一种基于流形分析和有限覆盖技术新发展起来的数值方法,计算精度高,且能够统一解决了连续介质力学问题、非连续介质力学问题以及块体运动学问题。而在土石坝工程计算中常常涉及到非连续位移计算和块体运动模拟等问题,因此采用数值流形法对土石坝工程进行更加合理的模拟是合适的。本文围绕数值流形法在土石坝工程中的应用,针对土石坝工程中的静力分析、边坡稳定分析、坍塌过程模拟、永久位移计算、防渗墙受力分析等问题,对数值流形法本身及计算程序进行了相应的改进和研制,使得数值流形法能够应用于土石坝工程的计算中。论文的主要内容如下： 1.对数值流形法的理论进行了介绍,探讨了数值流形法的计算稳定性。并针对计算材料非线性问题对数值流形法进行了改进,在数值流形法中加入了E-B模型和内蕴时间模型,给出了相关的计算流程,并对内时理论的硬化函数进行了研究。使得数值流形法在能够同时解决几何非线性和材料非线性问题。 2.将带E-B模型的数值流形法引入土石坝非线性静力分层加载计算中,并研制了相关的计算程序。将计算结果与传统的有限元计算结果进行了对比。利用内时数值流形法,将防渗墙与坝体之间考虑成分离的介质,对防渗墙进行了静力分析,地震动力响应分析,并分析了地震作用后坝顶出现裂缝的原因。采用内时数值流形法对土石坝进行了三维静力分析和地震永久变形分析,给出了三维地震永久变形分布图。 3.基于数值流形法的计算特点,提出了将数值流形法单元进行分离的方式来实现土体破坏的模拟,并给出了模拟土体破坏的计算流程。弥补了有限元法模拟剪切试验难以产生非连续位移的缺陷。对土的直剪试验,给出了相关的计算结果。结合增加重力法,将此方法应用于土石坝的边坡稳定分析和滑坡过程的模拟。讨论了该方法中块体边界的粘聚力和摩擦角对边坡安全系数的影响以及最终坍塌形态的影响。基于以上研究,对数值流形法进行了改进,构建了完整的基于数值流形法的土石坝静力、动力、边坡稳定分析的理论、数值方法和计算程序,为土石坝的稳定分析提供了新的分析途径和方法。
[Abstract]:In recent years, the construction of large high earth and rock dams, especially in strong earthquake areas, is increasing day by day. Therefore, using more accurate and reasonable calculation methods for earth and rock dams can not only find out the hidden safety problems existing in the existing projects. The numerical manifold method is a new numerical method based on manifold analysis and finite coverage technology. Moreover, the problems of continuum mechanics, discontinuous media mechanics and block kinematics can be solved in a unified way. However, discontinuous displacement calculation and block motion simulation are often involved in the calculation of earth and rock dams. Therefore, numerical manifold method is suitable for more reasonable simulation of earth-rock dam engineering. This paper focuses on the application of numerical manifold method in earth-rock dam engineering, aiming at static analysis, slope stability analysis, collapse process simulation, permanent displacement calculation, force analysis of impervious wall, etc. The numerical manifold method itself and its calculation program have been improved and developed accordingly, so that the numerical manifold method can be applied to the calculation of earth-rockfill dam engineering. The main contents of this paper are as follows:. 1. The theory of numerical manifold method is introduced, the computational stability of numerical manifold method is discussed, and the numerical manifold method is improved to solve the problem of material nonlinearity. The E-B model and intrinsic time model are added to the numerical manifold method. The related calculation flow is given and the hardening function of the internal time theory is studied so that the numerical manifold method can solve the geometric nonlinearity and material nonlinearity at the same time. 2. The numerical manifold method with E-B model is introduced into the calculation of nonlinear static stratified loading of earth-rock dam, and the related calculation program is developed. The results are compared with the traditional finite element method, and the internal time numerical manifold method is used. Considering the separation medium between the impervious wall and the dam body, the static analysis and the seismic dynamic response analysis of the impervious wall are carried out. The causes of cracks at the top of the dam after earthquake action are analyzed. The 3-D static analysis and seismic permanent deformation analysis of earth-rock dam are carried out by using the internal time numerical manifold method, and the distribution map of three-dimensional seismic permanent deformation is given. 3. Based on the computational characteristics of numerical manifold method, a method of separating numerical manifold method elements is proposed to simulate soil failure. The calculation flow of simulating soil failure is given, which makes up for the defect that it is difficult to produce discontinuous displacement in the finite element method. For the direct shear test of soil, the relevant calculation results are given, and the method of increasing gravity is combined with the method of increasing gravity. This method is applied to the slope stability analysis and landslide process simulation of earth-rock dams. The influence of the cohesive force and friction angle of the block boundary on the slope safety factor and the final collapse shape in this method is discussed. Based on the above research, the numerical manifold method is improved, and a complete theory, numerical method and calculation program for static, dynamic and slope stability analysis of earth-rock dam based on numerical manifold method are constructed. It provides a new way and method for stability analysis of earth-rock dam.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TV641

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