【作者】 王爱民；

【导师】 刘宝仁；

【作者基本信息】 吉林大学 ， 建筑与土木工程， 2005， 硕士

【摘要】 本文以浙江杭州七格污水处理厂等抗拔桩静载荷试验为背景,对抗拔单桩的承载力计算、上拔量计算、抗拔桩侧阻发展机理进行了分析研究,并结合当前国内抗拔桩施工的现状,对以支盘桩为代表的抗拔桩施工新工艺的应用进行了分析研究。首先介绍了抗拔桩的破坏模式,并在此基础上分析研究了等截面抗拔单桩的破坏模式和单桩极限承载力计算。抗拔单桩的破坏模式主要有以下三种:(1)沿桩—土侧界面剪破;(2)与桩长等高的倒锥台剪破;(3)复合剪切面破坏。一般而言,特别是长桩,发生第一种破坏模式。结合实测资料,推导出了单桩极限承载力及相应变形的计算公式。(1)根据粉土的性质,建立了桩—桩周粉土协调变形模式,推导出等截面抗拔单桩极限承载力公式及相应的位移公式,并与试验结果进行了比较;(2) 本文从桩基荷载传递规律的剪切位移模式出发,推导出抗拔单桩荷载与位移的理论解,并与室内模型试验结果进行比较;(3)通过对通用理论解的理解,使之与工程结合,解决了工程中的问题。分析结果表明,本文提出的计算式具有很好的计算精度。对扩底桩的受力及变形机理进行了分析,并在此基础上探讨影响抗拔桩承载力和上拔量的主要因素,并对扩底桩极限承载力的计算提出了计算方法。影响扩底桩抗拔形态的因素很多也很复杂,随着施工方法、基础深度以及土的物理力学性质而变化,因此要预先确定扩底抗拔桩的破坏形态非常困难,计算抗拔力时,宜多设几种可能的破坏面,择其抗力最小的作为最危险滑动面;扩底抗拔单桩的扩大头作用非常明显,能更多还原

【Abstract】 In this paper, based on the static-load tests of the tension piles on the province of Zhejiang such as Hang Zhou Qige Sewage Treatment Plant Project, etc, the calculations of ascending displacement, developing mechanism of the side friction and utmost bearing capacity of the tension piles are studied. And combined with the developing of the tension piles, the techniques of the construction are studied such as the squeezed branch with antipulling behavior. Failure modes of the tension piles are introduced first. Based on the failure modes, the utmost bearing capacity calculations of the engineering practice data, one method to calculating utmost single-pile bearing capacity is provided after simulating the uniform-section pile side friction. The failure modes of the single tension pile to mainly have three kinds of the following: (1)Follow the pile-the soil side interface shears to break; (2) The shear failure mode of the inverse cone similar to the pile height shear failure; (3)The compound shear failure. General, long piles especially, take place the first failure mode. Combine to measure the data actually, deduce the utmost bearing capacity and the calculation formula that correspond to transform. (1)According to the property of the silty soil, built up the transform mode of the pile -silty soil, deducing the utmost single-pile bearing capacity formula and the transform formula, and with experimented the result to carry on the comparison .Due to the regulation of the mode for shear transform , deduce the single tension pile solution of theory, and experiment the result with indoor model to carry on the comparison . (3)Learning the solves to the in general use theories, make it combined with the engineering, resolved the problem in it .Analyze the result enunciation, the calculation type that this text put forward has the good calculation accuracy. Be subjected to the stress and transformed mechanism ,carry on the analysis towards expanding the exploding bottom pile ,Explore a reason for the utmost bearing capacity and the correlative displacement , pull out main factor of the quantity ,To expanded the calculation that an extreme limit of bottom loads the dint to put forward the calculation method .The influence of the expanding bottom pile modality look quite a few and very complex .Along with the construction method, the foundation depth and the physics mechanics property but varieties of the soils, make sure the failure modality that the bottom pile in advance very difficult .When compute the stress of tension , it is proper to establish several more possible failure modality, choosing the conduct and actions that it resists the ability least as the most dangerous slip surface .A function of extension of single bottom pile is very obviously, can raise the utmost bearing capacity biggest .The utmost bearing capacity that it provide has the greatly percent of the total .The expanding bottom pile is not only improve the ultimate bearing resistance, but also improve the pile antipulling function .The usage of the expanding bottom tension pile , can lower the engineering investment effectively, and can raise the safety degree of the pile . The squeezed branch pile was always accepted to the press foundation. The research and application of the antipulling capability was little, it was often neglected its antipulling capability. Its shape and its special construction crafts not only raised the utmost bearing capacity to press, and but also raised it to lift. Combine the current local a present condition of construction, analyzed更多还原