带支锚环梁基坑支护体系有限元模拟及受力分析

发布时间：2019-01-27 10:57

【摘要】：深基坑支护结构中，环梁支护结构由于形成空间刚架作用，因此具有整体刚度大，受力性能好，施工方便等特点，在实际工程中得到了广泛的应用。国内外学者针对环梁支护也已进行了大量的研究，虽然目前环梁支护结构的设计计算方法还不很完善，但环梁的基本受力特性和工作性状已经基本被了解，现有的理论基本能够指导实际工程的应用。而对于带支锚的环梁支护结构近些年来虽然已有工程实例，但对其缺乏深入的研究，对其工作性能还不明确。根据目前深基坑带支锚环梁支护结构的工程实例，结合国内外在该领域已取得的研究成果，采用大型有限元分析软件MIDAS-GTS对带支锚的环梁支护结构的力学性状展开深入的研究，主要工作如下： 1、总结了目前环梁支护结构在国内外研究和应用的现状及主要的计算方法，分析了各种方法的优缺点及存在的问题。 2、介绍了论文涉及的有限元理论，土力学方面的土的应力、应变理论，土的强度准则、弹塑性本构模型及有限元分析软件MIDAS-GTS和理正深基坑软件。 3、采用MIDAS-GTS建立某基坑三维空间有限元模型，分析时把土体，围护桩、支撑和预应力锚索当成一个三维空间体进行计算，分析了带支锚环梁支护结构的内力和变形特点，另分析比较了锚索预应力大小、支撑刚度和位置等因素对环梁支护结构的受力和位移的影响。 4、采用MIDAS-GTS建立某工程实例整体空间有限元模型进行设计计算，将结果与理正深基坑的计算结果进行对比，并就两者计算结果的差异进行分析，以供以后类似工程参考。
[Abstract]:In the deep foundation pit supporting structure, the ring beam support structure has been widely used in practical engineering because of its large stiffness, good mechanical performance and convenient construction because of the formation of space rigid frame. Scholars at home and abroad have also done a lot of research on ring beam support. Although the design and calculation method of ring beam support structure is not perfect at present, the basic mechanical characteristics and working characteristics of ring beam support structure have been basically understood. The existing theories can guide the application of practical engineering. In recent years, though there have been some engineering examples for the ring beam supporting structure with supported anchors, it is lack of deep research and its working performance is not clear. According to the engineering example of deep foundation pit with bolted ring beam support structure at present, combined with the domestic and foreign research results in this field, In this paper, the mechanical properties of ring beam supporting structure with supported anchor are studied by using the finite element analysis software MIDAS-GTS. The main work is as follows: 1. The current research and application of ring beam supporting structure at home and abroad and the main calculation methods are summarized. The advantages and disadvantages of various methods and the existing problems are analyzed. 2. The finite element theory, stress and strain theory of soil mechanics, strength criterion of soil, elastic-plastic constitutive model, finite element analysis software MIDAS-GTS and Lizheng deep foundation pit software are introduced. 3. The three-dimensional finite element model of a foundation pit is established by MIDAS-GTS. The soil mass, retaining pile, bracing and prestressed anchor cable are considered as a three-dimensional space body in the analysis, and the characteristics of internal force and deformation of braced bolted ring beam supporting structure are analyzed. In addition, the influence of prestressing force, stiffness and position of anchor cable on the stress and displacement of ring beam supporting structure is analyzed and compared. 4. MIDAS-GTS is used to build the whole space finite element model of a project example to carry on the design calculation, the result is compared with the calculation result of the deep foundation pit of Lizheng, and the difference between the two calculation results is analyzed for the reference of the similar engineering in the future.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU470

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