Study On P-Y Curve Method For Computing Laterally Loaded Piles Under Horizontal Distribution Loads

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.