PHC管桩桩土相互作用承载特性及影响因素研究

发布时间：2018-09-11 15:06

【摘要】：PHC管桩作为提高地基承载力、满足特大工程的需要在我国越来越应用广泛。但由于PHC管桩桩土相互作用的复杂性，理论研究还不成熟，这就需要工程界不断提出新问题，，解决新问题，使理论日益完善，为工程实践更好的服务。本文以理论研究为基础，结合工程实例，利用FLAC3D软件对静载作用下PHC管桩桩土相互作用的承载特性及相关影响因素进行研究，主要的研究成果如下：（1）介绍了PHC管桩桩土相互作用的发展及应用现状，并对PHC管桩桩土相互作用的现场试验研究、理论分析研究及数值模拟研究等研究方法进行归纳和总结。（2）概括了静载作用下PHC管桩桩土相互作用承载特性的基本理论，介绍了影响单桩荷载传递的因素，并对时间效应、挤土效应、土塞效应及单桩的破坏形式做了简单的介绍。（3）根据FLAC3D软件的基本知识，利用FLAC3D软件，结合工程实例，对静载作用下PHC管桩桩土相互作用承载特性进行模拟，并对计算结果进行对比分析，进而说明了在静载作用下用FLAC3D软件模拟PHC管桩桩土相互作用的承载特性是可行的，为研究相关影响因素提供了依据；通过规范解与模拟值进行比较，得出了根据规范设计的PHC管桩是比较保守的，考虑桩土相互作用，利用修正的单桩极限承载力公式计算的结果与模拟值基本吻合，为PHC管桩在设计、实际施工及检测中，提供可靠的参考。（4）分别取不同接触面参数、不同桩径、不同桩长、不同土的弹性模量、不同桩的弹性模量等影响因素在静载作用下对PHC管桩桩土相互作用进行模拟并对其进行分析，结果表明改变接触面参数、改变桩径、改变桩长对PHC管桩桩土相互作用的影响很明显，而改变土的弹性模量和桩的弹性模量对PHC管桩桩土相互作用的影响不明显。在实际工程中，可适当的通过改变桩径、桩长及桩土接触面参数来完善对PHC管桩的优化设计，以达到节约成本的目的。
[Abstract]:PHC pipe pile is more and more widely used in our country to improve the bearing capacity of foundation and to meet the needs of large projects. However, due to the complexity of the interaction of PHC pipe, pile and soil, the theoretical research is still immature, which requires the engineering community to constantly put forward new problems, solve new problems, make the theory more perfect, and serve engineering practice better. On the basis of theoretical research and combined with engineering examples, this paper studies the bearing characteristics and related influencing factors of PHC pile-soil interaction under static load by using FLAC3D software. The main research results are as follows: (1) the development and application of PHC pipe pile-soil interaction are introduced, and the field test of PHC pipe pile-soil interaction is studied. The theoretical analysis and numerical simulation are summarized. (2) the basic theory of PHC pile-soil interaction under static load is summarized, and the factors influencing the load transfer of single pile are introduced. The time effect, soil squeezing effect, soil plug effect and the failure form of single pile are simply introduced. (3) according to the basic knowledge of FLAC3D software, using FLAC3D software, combined with engineering examples, The load-bearing characteristics of PHC pipe pile-soil interaction under static load are simulated, and the calculated results are compared and analyzed. The results show that it is feasible to simulate the bearing characteristics of PHC pipe pile-soil interaction by using FLAC3D software under static load. The results show that the design of PHC pipe pile according to the code is conservative, and the interaction between pile and soil is considered. The calculated results of the modified formula for the ultimate bearing capacity of single pile are in good agreement with the simulated value, which provides a reliable reference for the design, practical construction and inspection of PHC pipe pile. (4) different contact surface parameters and different pile diameters are taken separately. The influence factors such as different pile length, different soil elastic modulus and different pile elastic modulus are simulated and analyzed under static load. The results show that the contact surface parameters are changed and the pile diameter is changed. The influence of changing pile length on the pile-soil interaction of PHC pipe is obvious, but the influence of changing the elastic modulus of soil and the elastic modulus of pile on the pile-soil interaction of PHC pipe is not obvious. In practical engineering, the optimization design of PHC pipe pile can be improved by changing pile diameter, pile length and pile-soil contact surface parameters, in order to achieve the purpose of saving cost.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1

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