【作者】 姚泽良；

【导师】 简政；

【作者基本信息】 西安理工大学 ， 结构工程， 2003， 硕士

【摘要】 在桩基工程实际中，应用最广的是在竖向荷载下作用的桩。桩的极限荷载的确定关系到设计是否安全和经济的重要问题。国内外关于单桩竖向极限承载力的确定方法很多，但至今还未找到较为完善、科学和经济的方法求解桩的极限承载力。为此，本文对单桩极限承载力计算方法进行研究。 本文在对现有的单桩极限承载力计算方法进行系统的分析研究基础上，比较系统的对国内外所提出的各种方法对比分析与评价，可为桩基设计提供一定的参考。 本文着重讨论了在不同桩长、桩径和桩径比情况下，用静力法、经验法和《桩基荷载传递机理有限元程序》来研究单桩极限承载力值的变化规律，为此，编制了两个计算程序。所得重要结论具有明显的经济价值和现实意义。 本文将桩长、桩径分别变化7次，在7种不同的均质土中，利用Super软件剖分网格，将译码得到的数据文件调入前处理程序，然后进入《桩基荷载传递机理有限元程序》，经后处理程序处理后，分析在7种不同均质土中，不同桩长、桩径的桩的P-S曲线，从而得到各种情况下单桩极限承载力。为了分析以上得到的343组数据，本文采用多元线性回归分析法对其进行分析，并编制了多元线性回归分析方法的程序。提出了基于《桩基荷载传递机理有限元程序》的经验公式。经与其他方法进行对比计算，表明了该方法是可行的，可用此方法方便的估算出桩的承载力。 本文同时还研究了在相同的承载力要求下，可以满足承载力要求的不同桩长、桩径组合，从经济的角度出发，进行了对比分析，在中、高层建筑中具有应用价值。更多还原

【Abstract】 Vertically loading single piles are the most abroad on the design of the pile foundation. There are many methods in the world, which can calculate the ultimately bearing capacity of single pile. But all these methods aren’ t perfect, scientific or economical. Accordingly, this paper mainly researches about the calculating methods of the single pile.Firstly, this paper systematically summarizes and contrastively analyses the currently calculating methods of the single pile so as to provide with a reference on the pile design.Secondly, this paper importantly uses the finite element method, the static force method, the experiential method to analyse the single piles, which have different pile length, pile radius, the ratio of the pile length and radius. And in order to calculate the bearing capacity, the paper compiles two calculating programs based on the static force method, the experiential method. According to the calculated results, this paper gets some valuable conclusion by analysis, which can be used in practice.Thirdly, this paper analyzes seven different pile-length and pile-radius at seven different even soils, using the Super software to make grids, the front auxiliary program, the Finite Program of Pile Foundation and the behind auxiliary program, so that all piles’ P-S curves are analyzed. From the curves, every pile’ s ultimately bearing capacity is gotten. There are 343 group data. In order to analyze these data, the paper uses the plural linear programminganalysis method and compiles the program. Using this program, this paper summarizes an experiential method. It is certificated that the method is applicable, economical and valuable in the pile foundation practice.Finally, some piles have different pile-length and pile-radius combination while their bearing capacities are same. This paper contrastively analyses these piles by the economical viewpoint. Some conclusions are useful and practical on the middle and high-rise building.更多还原