【作者】 张建伟；

【导师】 戴自航；

【作者基本信息】 福州大学 ， 岩土工程， 2006， 硕士

【摘要】 本文在总结和阐述推力桩的研究现状、计算方法的基础上,结合具体的工程实例对推力桩与土相互作用的问题展开了以下几方面的研究。首先,本文阐述了桩基的作用、适用条件、发展简史以及桩基础的分类,总结了水平受荷单桩的分析理论和计算方法,主要有弹性地基法、地基反力法和有限单元法、地基反力法又包括极限地基反力法、弹性地基反力法和弹塑性地基反力法。本文第三章着重介绍了有限单元法的发展、基本原理和分析步骤,并结合抗滑桩结构详细阐述了弹性地基杆系有限元法的理论、基本原理和具体的分析过程。其次,本文对国外较为流行的在集中荷载作用下推力桩计算p -y曲线法进行了分析、对差分方程的基本理论进行了详细的介绍,并把p -y曲线法和有限差分法相结合来着重研究分布荷载作用下推力桩的计算问题,采用MATLAB语言编制了相应的p -y曲线有限差分法计算全桩位移、内力及图形处理程序。最后,利用本文提出的p -y曲线有限差分法对工程实例进行了计算,并与弹性地基杆系有限元法的计算结果或实测数据进行了对比分析,验证了该方法在分析分布荷载推力桩方面的可行性。进而对影响分布荷载推力桩承载能力的诸多因素进行了分析。结果表明:荷载大小是影响桩身位移和弯矩的主要因素之一; 桩周土的物理力学特性也将直接影响桩-土相互作用性状,进而影响推力桩的承载能力,土的强度和刚度越大,则桩的承载力越高; 提高桩身混凝土强度等级不能明显提高推力桩的承载能力; 一定程度上增大桩的截面尺寸可提高推力桩的承载能力,但当截面尺寸增大到某种程度时,桩的承载力提高不再明显。算例分析表明,本文所提出的计算方法方便可靠,且当有限差分段划分得足够小时,可使数值解接近于真实解,为p -y曲线法在分布荷载推力桩计算方面进行了新的探索,有助于推动p -y曲线法在分布荷载推力桩设计计算中的应用和研究。更多还原

【Abstract】 Based on the summary and narration on the present research situation of laterally loaded pile and calculation methods, combining the practical engineering examples, several aspects of reaserch on interactions between laterally loaded piles and soils are done as follows. First, the functions, the suitable conditions, the brief development history and the classification of the pile foundations are introduced; the analytical theories and calculation methods of the single horizontally loaded pile are summarized in this thesis. The foundation reaction method, the elastic foundation method and the finite element method are the mainly methods and the first one includes the limit foundation reaction method, the elastic foundation reaction method and the elastic-plastic foundation reaction method. The development situation, the basic principles and the analyzing steps of the finite element method are introduced emphatically in chapter 3 in this thesis. And the theory, the basic principle and the concrete analyzing process of the finite element method of elastic foundation link systems are introduced in detail by combining the anti-sliding pile. Next, the p-y curves method which is popular in oversea in the calculation of laterally loaded piles under concentrative loads is analyzed. The basic theory of difference equations is also intrduced detailedly; and the calculation problem of laterally loaded pile under distribution load is studied emphatically by combining the p-y curve method and the finite difference method. The p-y curves finite difference method which can compute the entire pile’s displacements and internal forces is programed in MATLAB language. The post-treatment of the computation results is also programed. Finally, the project examples are computed by using the p-y curve method mentioned in the thesis. The results are compared with measurements or that of the finite element method of elastic foundation link systems. All shows that this method is feasible in analyzing laterally loaded piles under horiaontal distribution loads. Then the factors which may influence the bearing capacity of the laterally loaded pile under horizontal distribution load are analyzed. The results indicate that, the bending moment and displacement of the pile are influenced mainly by the outside load. The behavior of the pile-soil interaction is influenced directly by the physical and mechanical characteristics of the soils around the pile. And further, they influence the bearing capacity of the laterally load pile. The bigger the intensity and rigidity of the soil, the higher the bearing capacity of the pile. The bearing capacity of the pile can not be improved obviously by increasing the concrete intensity rank. However, for some extent, the bearing capacity of the pile can be improved by increasing the section size, but the bearing capability can not be improved obviously when the section size of the pile increases to certain degree. Analysises on project examples show that the computation method presented in this thesis is convenient and reliable. And the numerical solution can approach to the real solution if the limited difference partitions are divided small enough. Some new exploration for the p-y curve method which is used in the computation of the laterally loaded pile under distribution load is made. And it is helpful to promote the application and research for the design and calaulation of the laterally loaded pile under distribution load by using the p-y curve method.更多还原