软土地基堆煤荷载下桩基变形与受力分析研究

发布时间：2018-01-22 07:10

本文关键词： 软土地基桩基堆载桩土相互作用有限元　出处：《浙江大学》2013年硕士论文　论文类型：学位论文

【摘要】：在软弱土地基中,大面积堆载不仅会导致地基沉降,还会使地基土体产生侧向位移,地基土体的侧向位移会在桩基上产生水平荷载作用,使得桩基产生附加的弯矩和变形,进而可能导致结构破坏。另一方面,地面堆载导致桩周地基土产生固结沉降,土相对桩有向下的位移,在桩身产生负摩擦力,进而增加了桩的轴向荷载并产生附加沉降,往往造成不均匀沉降。本文结合北仑电厂堆载预压工程,通过三维有限元软件ABAQUS,在考虑桩基和土体相互作用的基础上,对堆载下桩基的受力变形性状进行了分析。本文主要工作如下： (1)本文首先通过对加载方式、不同模型简化等方面对模型进行了比选,从而选择了能够反映出桩土受力实际情况且能兼顾计算机的合理模型。 (2)在该模型基础上,得到在逐层堆载下桩的侧向变形和桩顶沉降、场地地基的变形情况以及桩身的弯矩和应力,并将计算结果与实测结果进行了对比,有较好的一致性。 (3)根据计算分析得到的桩身弯矩分布规律,提出了不同堆载情况下桩身最大弯矩的估算公式,可简单有效的估算桩身弯矩,初步指导工程设计和施工。 (4)对堆载位置、堆载荷重进行参数敏感性分析,研究其对场地整体沉降、桩顶沉降、桩顶侧移、桩身最大侧移等方面计算结果的影响。同时,也分析了有桩和无桩对场地土体变形的影响。
[Abstract]:In the soft soil foundation, the large area surcharge will not only cause the foundation settlement, but also make the foundation soil produce the lateral displacement, the lateral displacement of the foundation soil will produce the horizontal load action on the pile foundation. On the other hand, the ground load results in consolidation settlement of the soil around the pile, and the soil has the downward displacement of the pile, resulting in negative friction in the pile body. Furthermore, the axial load of pile is increased and additional settlement is produced, which often results in uneven settlement. In this paper, combined with Beilun Power Plant surcharge preloading engineering, through the three-dimensional finite element software Abaqus, on the basis of considering the interaction between pile foundation and soil. The deformation behavior of pile foundation under surcharge is analyzed. The main work of this paper is as follows: In this paper, the loading mode and the simplification of different models are compared and selected firstly, and then a reasonable model which can reflect the actual situation of pile-soil force and give consideration to computer is selected. 2) on the basis of the model, the lateral deformation and the settlement of the pile top, the deformation of the site foundation, the bending moment and stress of the pile body are obtained, and the calculated results are compared with the measured results. There is good consistency. 3) according to the distribution law of bending moment of pile body obtained by calculation and analysis, the estimation formula of maximum bending moment of pile body under different heaped load is put forward, which can estimate pile bending moment simply and effectively, and guide the design and construction of engineering. (4) the sensitivity of the parameters to the position and weight of the pile load is analyzed, and the influence of the parameter sensitivity on the settlement of the site, the settlement of the top of the pile, the lateral displacement of the top of the pile and the maximum lateral displacement of the pile body are studied. At the same time. The influence of pile and pile on soil deformation is also analyzed.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU473.1

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