竖向荷载对填芯管桩水平承载性能的影响

发布时间：2019-02-17 13:01

【摘要】：影响管桩水平承载性能的因素很多,主要包括桩周土土体强度、桩身强度、桩长、桩身截面大小、桩身竖向荷载大小、管桩填芯等。然而大多数关于管桩的水平承载性能的研究,只是改变某一个因素对管桩水平承载性能的影响,而忽略了桩水平承载性能是由多种因素相互影响相互作用而形成的一种外在的力学特性。因此考虑多种因素对管桩水平承载性能的影响,更加贴近工程实际。根据工程实际,管桩承受竖向荷载不可避免。因此本文通过考虑不同竖向荷载以及不同填芯强度情况下,通过室内试验以及数值模拟对管桩的水平承载性能进行对比研究。研究结果表明,水平加载初期水平荷载较小,桩身刚度远大于土体,桩身位移较小,水平承载主要靠土体抗力,桩顶位移主要有土体压缩产生,不同填芯及竖向荷载组合管桩的水平承载性能比较接近。水平加载中后期,桩身位移增大,管桩填芯部分及P-Δ效应作用明显,不同填芯及竖向荷载组合对管桩水平承载性能提高主要出现在水平荷载加载中后期;在不同竖向荷载及填芯组合对管桩的水平承载性能的数值模拟研究中发现,存在最优竖向荷载及填芯组合对管桩的水平承载性能提高最大,当桩身位移较大或者出现倾斜时,最优管桩水平承载性能组合不是竖向荷载最大与填芯强度最高组合;当管桩桩身位移较小时,最优管桩水平承载性能组合为最大竖向荷载与最大填芯强度组合。
[Abstract]:There are many factors that affect the horizontal bearing capacity of pipe piles, including soil strength, pile body strength, pile length, pile cross-section, vertical load, core filling and so on. However, most researches on the horizontal bearing capacity of pipe pile only change the influence of one factor on the horizontal bearing capacity of pipe pile. The lateral bearing capacity of pile is a kind of external mechanical property which is formed by the interaction of many factors. Therefore, considering the influence of many factors on the horizontal bearing capacity of pipe pile, it is closer to engineering practice. According to the engineering practice, the vertical load of pipe pile is inevitable. In this paper, the horizontal bearing capacity of pipe pile is studied by laboratory test and numerical simulation considering different vertical loads and different core filling strength. The results show that at the initial stage of horizontal loading, the horizontal load is small, the stiffness of pile body is much larger than that of soil, the displacement of pile body is smaller, the horizontal load is mainly dependent on soil resistance, and the displacement of pile top is mainly caused by soil compression. The horizontal bearing capacity of different core-filled and vertical load composite pipe piles is similar. In the middle and late stage of horizontal loading, the displacement of pile body increases, and the effect of core filling and P- 螖 effect on pipe pile is obvious. The improvement of horizontal bearing capacity of pipe pile by different core-filling and vertical load combinations mainly occurs in the middle and late stage of horizontal load loading. In the numerical simulation of the horizontal bearing capacity of pipe piles under different vertical loads and core-filled combinations, it is found that there is an optimal vertical load and core-filled combination that can improve the horizontal load performance of pipe piles most, and when the displacement of pile body is large or inclined, The optimal combination of horizontal bearing capacity of pipe pile is not the combination of the maximum vertical load and the highest core-filling strength. When the displacement of pipe pile is small, the optimal combination of horizontal bearing capacity of pipe pile is the combination of maximum vertical load and maximum core filling strength.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1

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