基于ABAQUS对高速公路软土地基拓宽变形性状的应用研究

发布时间：2018-05-10 13:18

本文选题：高速公路 + 拓宽工程　；参考：《河北工业大学》2014年硕士论文

【摘要】：在软土地基高速公路拓宽工程中，普遍存在新、老路堤差异沉降的问题。而这个问题也成为高速公路改扩建工程中的重要问题。为解决差异沉降给工程带来的不利影响，国内外的工程技术人员都进行了大量的工程实践，虽然在已完成的拓宽工程中取得了一些宝贵的经验，但相关的理论成果较少，没有系统性的规范，对新老路基的沉降特性了解的也不是很全面，需要作进一步的研究。本文以北方某高速公路的拓宽工程为背景，从软土地基上实际出现的问题出发，基于ABAQUS有限元分析，通过数值模拟对新老路堤的沉降特性进行了系统的研究，主要内容如下： 1.介绍了有限元法和ABAQUS的基本概况，建立了路基拓宽的有限元模型，分别分析了无处理措施时路基的沉降、附加应力以及超孔压变形。结果表明：新路基以附加荷载形式作用于老路基，，从而引起了新老路基的不均匀沉降变形；路基顶面竖向沉降沿路基横断面方向由路中心向两侧呈勺型分布；新路基水平位移的最大值出现在新路基的形心位置；新路堤填土处出现了附加剪应力集中。 2.建立水泥搅拌桩复合地基模型，分析填土与桩体参数的改变对拓宽路基沉降变形的影响。结果表明：路基的变形情况会随填土和桩体设计参数的变化而改变，路堤填土和桩基对路基的稳定都有着至关重要的影响，选择有效的工艺参数才能最有效的控制路基的变形。 3.阐述了PTC管桩在地基处理时的作用机理，分析了PTC管桩复合地基对路基沉降变形的影响。结果表明：PTC管桩复合地基处理措施增加了软土路基的总体刚度，整个地基变形向深部传递。在桩土的相互作用中，PTC管桩内、外侧摩阻力异步发挥，土芯和桩壁之间产生比较大的摩阻力，使得土芯和桩壁一起下沉，桩呈类似闭口桩的破坏形式。
[Abstract]:The problem of differential settlement between old and new embankments is common in the widening project of expressway with soft soil foundation. And this question also becomes the important question in the highway reconstruction and extension project. In order to solve the adverse effects of differential settlement on the project, many engineers and technicians at home and abroad have carried out a large number of engineering practices. Although some valuable experience has been obtained in the completed widening project, there are few related theoretical achievements. Without systematic specification, the settlement characteristics of new and old subgrade are not fully understood, and need to be further studied. In this paper, the settlement characteristics of new and old embankment are systematically studied by numerical simulation based on ABAQUS finite element analysis and based on the actual problems on soft soil foundation based on the widening project of a highway in the north. The main contents are as follows: 1. This paper introduces the basic situation of finite element method and ABAQUS, establishes the finite element model of roadbed widening, and analyzes the settlement, additional stress and superpore pressure deformation of roadbed without treatment measures respectively. The results show that the new roadbed acts on the old roadbed in the form of additional load, which causes the uneven settlement of the new and old roadbed, and the vertical settlement of the top surface of the roadbed distributes along the cross-section of the roadbed from the center of the road to the two sides of the roadbed. The maximum horizontal displacement of the new embankment appears in the center of the new roadbed and the additional shear stress concentration appears at the new embankment fill. 2. The model of cement mixing pile composite foundation is established, and the influence of the change of filling and pile parameters on the settlement deformation of widening roadbed is analyzed. The results show that the deformation of embankment will change with the change of the design parameters of embankment and pile. The embankment filling and pile foundation have an important influence on the stability of roadbed. The most effective control of subgrade deformation can be achieved by selecting effective technological parameters. 3. This paper expounds the action mechanism of PTC pipe pile in foundation treatment, and analyzes the influence of PTC pipe pile composite foundation on subgrade settlement and deformation. The results show that the total stiffness of soft soil subgrade is increased and the deformation of the whole foundation is transmitted to the deep. In the pile-soil interaction, the lateral frictional resistance of PTC pipe pile plays asynchronously, and the friction between the soil core and the pile wall causes the soil core to sink together with the pile wall, and the pile is similar to the closed pile.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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