刚柔组合桩在山区公路软土地基中的应用研究

发布时间：2018-07-03 16:59

本文选题：刚柔组合桩 + 复合地基　；参考：《重庆交通大学》2014年硕士论文

【摘要】：近年来，我国经济迅速发展，国家越来越注重基础工程建设，尤其是公路建设。西部大开发以来，西部地区高速公路建设高速发展，，而西部地区的地形地貌严重的制约了其发展速度，其中山区软土地基处理是一个很重要的原因。因此，研究山区软土地基的特性以及处理方法是西部高速公路发展的一个重要课题。目前，复合地基在处理山区软土地基过程中发挥了重要作用。刚柔组合桩复合地基是近年来提出来的一种复合地基形式，其主要的工作机理为：充分利用柔性桩提高浅层的地基承载力；发挥刚性桩的工作特性，有效的控制复合地基沉降以及提高整个复合地基的地基承载力。目前，国内外对此还没有比较系统深入的研究，更没有比较完善的设计理论和计算方法，因此对其研究是十分有必要的。本文主要依托“贵州省交通厅科技项目——贵州山区高速公路软基处理关键技术研究与示范工程”，收集分析总结了相关已有研究成果，对软土地基的定义，软土地基在贵州山区的破坏形式以及处理方法进行了概述；综述了复合地基的承载力计算和沉降计算公式，为刚柔组合桩的承载力计算和沉降计算提供了依据；利用刚柔组合桩复合地基设计具体工程实例，其承载力计算结果和沉降量均能达到设计要求，并与其他处理方法进行比较，发现刚柔组合桩复合地基较其他处理方法可以有效的降低成本。此外，利用PLAXIS有限元软件，对刚柔组合桩复合地基进行了计算机施工数值模拟，并变换复合地基参数，研究各个因素对沉降的影响，得出了以下结论： ①褥垫层的厚度对刚柔组合桩复合地基沉降有明显的影响，垫层厚度与刚柔组合桩复合地基沉降呈非线性关系； ②刚性桩的桩长变化对刚柔组合桩的沉降变化影响很大。 ③柔性桩的桩长变化对刚柔组合桩的沉降变化影响不大。综上所述：研究结果为刚柔组合桩复合地基的应用提供理论依据，对进一步发挥刚柔组合桩复合地基在软基处理上的优势提供了现实意义，为保证贵州省交通安全提供了实用价值。
[Abstract]:In recent years, our country economy develops rapidly, the country pays more and more attention to the basic engineering construction, especially the highway construction. Since the development of the western region, the highway construction in the western region has developed at a high speed, but the terrain and geomorphology in the western region have seriously restricted its development speed, among which the soft soil foundation treatment in the mountainous area is a very important reason. Therefore, studying the characteristics and treatment methods of soft soil foundation in mountainous area is an important subject in the development of western expressway. At present, composite foundation plays an important role in the treatment of soft soil foundation in mountainous area. The composite foundation of rigid-flexible composite pile is a kind of composite foundation proposed in recent years. Its main working mechanism is to make full use of flexible pile to improve the bearing capacity of shallow foundation, to give full play to the working characteristics of rigid pile, Effectively control the settlement of composite foundation and improve the bearing capacity of the whole composite foundation. At present, there is no systematic and deep research on it at home and abroad, let alone perfect design theory and calculation method, so it is very necessary to study it. This paper mainly relies on the "key technology research and demonstration project of soft foundation treatment of highway in Guizhou mountainous area", and collects, analyzes and summarizes the related research results and the definition of soft soil foundation. The failure forms and treatment methods of soft soil foundation in Guizhou mountainous area are summarized, and the calculation formulas of bearing capacity and settlement of composite foundation are summarized, which provide the basis for calculation of bearing capacity and settlement of rigid-flexible composite pile. The calculation results of bearing capacity and settlement of composite foundation with rigid-flexible composite piles can meet the design requirements, and are compared with other treatment methods. It is found that the composite foundation of rigid-flexible composite pile can effectively reduce the cost compared with other treatment methods. In addition, by using PLAXIS finite element software, the numerical simulation of the composite foundation with rigid and flexible piles is carried out, and the parameters of the composite foundation are changed to study the influence of various factors on the settlement. The conclusions are as follows: (1) the thickness of cushion has obvious influence on the settlement of composite foundation with rigid-flexible composite pile, and the thickness of cushion has a nonlinear relationship with the settlement of composite foundation with rigid-flexible composite pile; (2) the variation of pile length of rigid pile has a great influence on the settlement of rigid-flexible composite pile, and the change of pile length of flexible pile has little effect on the settlement change of rigid-flexible composite pile. To sum up: the research results provide a theoretical basis for the application of the composite foundation of rigid and flexible composite piles, and provide practical significance for further exerting the advantages of the composite foundation of rigid and flexible composite piles in the treatment of soft foundation. It provides practical value for ensuring traffic safety in Guizhou province.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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