h型支挡结构性状分析

发布时间：2019-03-20 12:39

【摘要】：h型支挡结构作为较新式支挡结构,在工程实践中越来越广泛应用。本文以福建省宁德市某一边坡工程为研究对象,利用PLAXIS有限元软件对h型支挡结构进行数值模拟,采用Hardening-soil本构模型反映土体的加卸载性质,利用接触面单元模拟桩土作用。本文建立基本计算模型,分析h型支挡结构工作性状,研究在各种因素不同计算参数下的性状变化及潜在破坏模式。首先,对PLAXIS软件和有限元计算方法进行基本介绍,分析有限元相关材料单元的基本特性,根据不同本构模型的优缺点比较,决定采用硬化土本构模型并展开相关模型介绍,对强度折减法原理进行详细阐述。其次,建立基本计算模型,分析前后桩受力和变形特征,为了进一步揭示了h型支挡结构的工作机理,分别建立双排单桩和门架式支挡结构的数值模型,与h型支挡结构的受力和变形性能进行对比分析,更深入总结h型支挡结构性状特征。再次,展开各影响因素下h型支挡结构的性状分析,分别建立桩径、桩排距、嵌固深度、连系梁刚度、连系梁倾角、铰接体系、粘聚力、内摩擦角和压缩模量等各因素不同计算参数模型。根据分析结果,提出最优桩径、桩排距、连系梁尺寸及嵌固深度等,为优化h型支挡结构设计提供参考意见。然后,利用Phi-c程序进行h型支挡结构破坏机理分析,研究桩径、桩排距、嵌固深度、连系梁刚度、连系梁倾角、铰接体系、抗剪强度、压缩模量等各因素不同计算参数的可能滑移面,分析边坡潜在破坏模式。同时分析各因素计算参数与坡体稳定性关系。之后,进行工程实例分析,了解场区岩土地层特性和周围环境情况的基础上,对有限元数值模型进行合理概化。利用监测成果验证h型支挡结构实际支挡效果,同时与有限元模拟结果对比,验证有限元模型及参数的合理性。最后,总结本文所研究的主要内容以及取得的研究成果,同时,对今后进一步研究工作提出一些建议。
[Abstract]:H-type retaining structure, as a new type retaining structure, is more and more widely used in engineering practice. In this paper, a side slope project in Ningde City, Fujian Province is taken as the research object, the h-shaped retaining structure is numerically simulated by using PLAXIS finite element software, the Hardening-soil constitutive model is used to reflect the loading and unloading properties of the soil, and the pile-soil action is simulated by the contact surface element. In this paper, the basic calculation model is established to analyze the working character of h-type retaining structure, and to study the character change and potential damage pattern under various factors and different calculation parameters. Firstly, the PLAXIS software and the finite element calculation method are introduced, and the basic characteristics of the finite element related material element are analyzed. According to the comparison of the advantages and disadvantages of different constitutive models, it is decided to adopt the hardened soil constitutive model and expand the related model to introduce the basic characteristics of the finite element related material element. The principle of strength reduction method is described in detail. In order to reveal the working mechanism of h-type retaining structure, the numerical models of double-row single-pile and gantry retaining structure are established, respectively, in order to reveal the working mechanism of the h-shaped retaining structure, and establish the numerical model of the double-row single-pile and gantry retaining structure, respectively. Compared with the stress and deformation performance of h-type retaining structure, the characteristics of h-type retaining structure are further summarized. Thirdly, the behavior analysis of h-shaped retaining structure under the influence factors is carried out, and the pile diameter, pile row distance, embedded depth, stiffness of connecting beam, angle of connecting beam, hinge system and cohesive force are established, respectively. Different parameter models of internal friction angle and compression modulus. According to the analysis results, the optimum pile diameter, pile row distance, connecting beam size and embedded depth are put forward, which provide a reference for optimizing the design of h-type retaining structure. Then, the failure mechanism of h-shaped retaining structure is analyzed by Phi-c program. The pile diameter, pile row distance, embedded depth, stiffness of connecting beam, inclination angle of connecting beam, hinge system and shear strength are studied. The potential failure mode of slope is analyzed by the possible slip surface of different calculation parameters, such as compression modulus and so on. At the same time, the relationship between the calculation parameters of each factor and the stability of slope is analyzed. Then, the finite element numerical model is reasonably generalized based on the analysis of engineering examples and the understanding of the characteristics of geotechnical strata and surrounding environment in the field area. The actual retaining effect of h-type retaining structure is verified by the monitoring results, and the rationality of the finite element model and parameters is verified by comparing with the finite element simulation results. At last, the main contents and achievements of this paper are summarized. At the same time, some suggestions for further research are put forward.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU470

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