基于HSS模型的群体基坑开挖的性状及相互影响分析

发布时间：2018-12-26 15:31

【摘要】：随着城市建设规模的扩大和地下空间功能的多样化，出现了在城市里进行大规模的地下空间开发，多个基坑同步开挖或相继开挖，这就不可避免出现群体基坑相互作用问题。目前，国内外的研究多以单基坑为研究对象展开，少数学者对相邻基坑进行过研究，而对群体基坑的研究则寥寥无几。随着大型地下空间开发项目的增多，群体基坑问题必将越来越突出，准确分析群体基坑的内力及变形情况及其相互影响规律将有助于优化施工、节约成本。在总结三个大型群体基坑工程施工经验以及对各种常见土体模型进行分析的的基础上，运用大型岩土三维有限元分析软件Z-Soil.PC，针对不同开挖深度下的不同支护体系，土体采用HSS本构模型，建立相对应体系的三维有限元模型。其中，对放坡开挖的群体浅基坑进行了不同开挖顺序下的土体位移分析以及土体强度折减分析,分析过程中还考虑了地下水渗流的影响。对排桩支护的中等深度群体基坑进行了间距为2H的“田”字分布的群体基坑同时开挖的土体变形、支护结构受力及变形分析，并分析了基坑间距对土体变形、排桩内力及变形的影响。对地连墙与内支撑联合支护开挖的群体深基坑，，分析了先中间后两边依次开挖的群体基坑的土体变形及地连墙内力变化与侧向变形，并考虑了不同的开挖顺序和基坑间距对基坑土体位移和地连墙的受力、变形的的影响。通过以上分析，得出不同支护方式的群体基坑坑底隆起、坑间土堤的变形规律以及支护结构的内力和变形规律。并在此基础上，分析出了地下水渗流、土质、基坑间距、基坑开挖顺序等因素对群体基坑的影响。
[Abstract]:With the expansion of the scale of urban construction and the diversification of underground space functions, large-scale underground space development has emerged in the city, and several foundation pits have been excavated synchronously or successively, which inevitably leads to the problem of group foundation pit interaction. At present, most of the researches at home and abroad take single foundation pit as the research object. A few scholars have studied the adjacent foundation pit, but the research on the group foundation pit is very few. With the increase of large underground space development projects, the problem of group foundation pit will become more and more prominent. It will be helpful to optimize construction and save cost by analyzing accurately the internal force and deformation of group foundation pit and the law of mutual influence. On the basis of summing up the construction experience of three large group foundation pit projects and analyzing various common soil models, the large rock and soil three-dimensional finite element analysis software Z-Soil.PCis applied to different supporting systems under different excavation depths. The three-dimensional finite element model of the corresponding system is established by using the HSS constitutive model. Among them, soil displacement analysis and soil strength reduction analysis under different excavation sequence are carried out for the group shallow foundation pit excavated by slope, and the influence of groundwater seepage is also considered in the process of analysis. In this paper, the deformation of soil mass, the force and deformation of supporting structure, and the deformation of soil in the group foundation pit with the distribution of "field" with space of 2H are analyzed, and the deformation of soil is analyzed. The influence of internal force and deformation of row pile. In this paper, the deformation of soil mass and the variation of internal force and lateral deformation of the group foundation pit, which are excavated first in the middle and then on the two sides in turn, are analyzed for the group deep foundation pit which is excavated by the combined support of the ground connecting wall and the inner bracing. The influence of different excavation sequence and foundation pit spacing on the displacement of foundation pit soil and the force and deformation of the ground connecting wall are considered. Based on the above analysis, the deformation law of pit bottom uplift, interpit embankment and the internal force and deformation of supporting structure are obtained. On this basis, the effects of groundwater seepage, soil quality, foundation pit spacing and excavation sequence on the group foundation pit are analyzed.
【学位授予单位】：华侨大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU470

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