静压管桩沉桩过程桩周应力发展变化试验研究

发布时间：2018-02-20 21:00

本文关键词： 管桩模型试验桩侧压力摩阻力土床制备半解析半数值　出处：《石家庄铁道大学》2015年硕士论文　论文类型：学位论文

【摘要】：现阶段随着高层、超高层建筑的发展应用,桩基础在建筑结构中的应用越来越广泛。由于采用静压法工艺施工成型的管桩具有易于保证和检查的桩身质量,另外工程成本相对而言较低,且具有稳定性好、沉降量少而均匀、承载力高、沉降速度低等良好特性,从而使其成为现代工程系统中十分重要的基础形式。然而,目前对于管桩静压法施工时的研究尚不成熟,对于管桩的沉桩机理及其承载力研究相对于工程应用而言比较落后。在各个方面的研究中,单桩的贯入和静载试验是评定桩施工质量好否必不可少的检验方法,对其的研究也显得尤为重要。由于相对于桩基现场足尺试验,室内模型试验具有易于控制的试验工况和试验的可重复性,且在经济性方便相对于现场试验有很大的优越性,目前成为研究桩基沉桩及承载机理的非常重要的手段。为了分析静压管桩在沉桩过程中的桩身应力变化,探究静压法施工的桩基在沉桩及静载过程中的相关机理。本文通过学习总结以前学者们的研究方法及相关成果,并吸取相关静压桩的模型试验的经验。然后使用一种桩基试验测量的新方法来测量分析试验中桩基应力应变数据,其弥补完善了传统试验的不足和缺点。本文主要做了以下几方面的研究工作:针对本模型试验要求,开发了一种土床制备装置并进行了试验标定,得出了制备不同密实度土床的试验方法,制取的试验土床可满足试验精度的要求。试验运用一种新型的桩基试验测量方法,通过在模型管桩内壁粘贴十字花温度自补偿式应变片测量桩身应变值,然后使用一种数值分析方法来将应变反算为管桩在压入、静载过程中的摩阻力、端阻力以及侧压力。并通过理论与有限元软件建模分析验证此试验测试方法的可靠性,证明其在测量应用中表现匹配良好。利用自行设计的多功能静力压桩装置,其包括模型桩装置、加载装置、数据采集系统等一套完整的设备。试验中试验加载与测试设备试运行良好,为室内模型试验提供了良好的试验基础与环境。在一套可实现静压法压桩的试验设备基础上,本文做了一系列的模型试验。分为管桩的贯入和静载试验两部分。通过应变信息采集系统全程测量并记录了模型管桩在砂土中沉桩过程及静载过程中的应力应变变化,对管桩的沉桩过程及静载过程中桩身侧压力和摩阻力的变化规律进行了研究。
[Abstract]:At present, with the development and application of high-rise building and super high-rise building, pile foundation is more and more widely used in building structure. In addition, the engineering cost is relatively low and has good characteristics such as good stability, small and uniform settlement, high bearing capacity and low settlement speed, which makes it a very important basic form in modern engineering system. At present, the research on the static pressure method of pipe pile is not mature, and the research of pile sinking mechanism and bearing capacity of pipe pile is relatively backward compared with the engineering application. The penetration test and static load test of single pile is an essential test method to evaluate whether the pile construction quality is good or not, and the research on it is especially important. The indoor model test has the advantages of easy control and repeatability compared with the field test. At present, it has become a very important means to study pile driving and bearing mechanism of pile foundation. In order to analyze the stress change of static pressure pipe pile in the course of piling, This paper explores the mechanism of pile foundation under static pressure construction in the process of pile sinking and static loading. Then a new method of pile foundation test is used to measure and analyze the stress and strain data of pile foundation. It makes up for the shortcomings and shortcomings of the traditional test. The main research work in this paper is as follows: according to the requirements of the model test, a soil bed preparation device is developed and calibrated. The test method of preparing soil bed with different compactness is obtained, and the test soil bed can meet the requirement of test precision. A new method of pile foundation test and measurement is used in the experiment. The strain value of pile body is measured by sticking cross temperature self-compensating strain gauge into the inner wall of the model pipe pile, and then a numerical analysis method is used to calculate the strain back to the friction resistance of the pipe pile in the process of pressing in and static loading. The end resistance and lateral pressure. The reliability of the test method is verified by theoretical and finite element software modeling and analysis. It is proved that the test method matches well in the measurement and application. The self-designed multi-function static piling device is used. It includes a complete set of equipment, such as model pile device, loading device, data acquisition system and so on. It provides a good test foundation and environment for indoor model test. On the basis of a set of test equipment which can realize static pressure pressing pile, In this paper, a series of model tests have been done, which are divided into two parts: the penetration test and the static load test. The stress-strain changes of the model pipe pile in the process of piling and static loading are measured and recorded through the strain information collection system. The variation of lateral pressure and frictional resistance of pipe pile during piling and static loading are studied.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753.3

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