天津地区深基坑支护设计与施工研究

发布时间：2018-01-15 02:11

本文关键词：天津地区深基坑支护设计与施工研究　出处：《湖北工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：在城市建设的过程中,由于人口密度大、土地利用率逐渐提高,而基坑工程周边的环境往往非常复杂。地基土一般由一定层厚的第四季松散沉积物构成,如人工土层、粘土层、淤泥层、粉质粘土层、卵砾石层、淤泥质土层、砂层等,这些松散物构成土层在基坑开挖时,它的自稳高度是很有限的。地下水埋深较浅时,水压力作用在围护结构,对围护结构的侧向变形有很大影响,如果不用以有效防范,发生管涌、流砂、突涌等现象的可能性大大提高,从而加速基坑失稳破坏。建筑施工过程中深基坑工程造成的影响以及存在的不确定性因素太多,从目前的情况来看工程实践比相关的理论研究成果更加有利于工程建设的开展,现在很多工程都是通过施工经验来确定深基坑工程建设的具体方案,不过这种处理方式存在的问题很多,虽然很多建筑设计师都在对深基坑工程的支护技术进行了大量的研究,也进行了大量的实验来判断支护方案的可靠性,不过在实际运用的过程中仍然会发生安全事故。在建筑行业快速发展的阶段,怎样保证施工的进度、工程质量以及施工安全是业界需要去思考的问题,而其中基坑支护方案的选择是其中一项非常重要的工作,合理的选择支护方案不仅能够节约施工成本还能够尽可能的降低安全事故发生的概率。本文主要针对深基坑施工工艺以及深基坑动态施工的数值这两方面的内容进行研究。采用的研究方法主要有两种,第一种是对深基坑施工现场相关参数的监测,第二种是有限元分析法。将这两种方法结合起来分析以此来确定深基坑工程施工过程中围护结构的内部应力、基坑位移以及基坑岩土体等参数指标。造成基坑位移是由于土体被开挖导致的,而且进行基坑开挖会使得基坑中的应力指标出现变化:各种支护结构的适用范围都有所不同,因此不能够简单的判断这些支护技术的好坏,现阶段很多施工单位都采用钢管桩+锚杆这种支护,其主要作用是降低基坑位移值。在进行土体开挖时需要根据土层的结构特征以及施工单位拥有的技术来合理的选择支护方案而且尽可能的使得支护方案多样化,这样能够提高基坑的稳定性。
[Abstract]:In the process of urban construction, because of the large population density, the land utilization rate is gradually increased, and the surrounding environment of foundation pit engineering is often very complex. The foundation soil is usually composed of loose sediments in the fourth quarter of a certain layer thickness. Such as artificial soil layer, clay layer, silt layer, silty clay layer, gravel layer, silt soil layer, sand layer and so on. When the groundwater depth is shallow, the water pressure acting on the enclosure structure has a great influence on the lateral deformation of the enclosure structure. If it is not necessary to take effective precautions, piping and sand flow will occur. The possibility of sudden surge is greatly increased, which accelerates the failure of foundation pit instability. The influence of deep foundation pit engineering and the uncertainty factors are too many in the process of building construction. From the current situation, engineering practice is more conducive to the development of engineering construction than related theoretical research results. Now, many projects are based on construction experience to determine the specific project of deep foundation pit construction. However, there are many problems in this way, although many architects have done a lot of research on the support technology of deep foundation pit engineering, and a large number of experiments have been carried out to judge the reliability of the support scheme. However, in the process of practical application, there will still be safety accidents. In the stage of rapid development of the construction industry, how to ensure the progress of construction, engineering quality and construction safety is a problem that the industry needs to think about. Among them, the selection of foundation pit support scheme is one of the very important work. Reasonable selection of supporting scheme can not only save the construction cost but also reduce the probability of safety accidents as far as possible. This paper mainly focuses on the deep foundation pit construction technology and the numerical value of deep foundation pit dynamic construction. There are two kinds of research methods. The first is to monitor the relevant parameters of deep foundation pit construction site, the second is the finite element analysis method. The two methods are combined to determine the internal stress of the retaining structure in the construction process of deep foundation pit. The displacement of foundation pit is caused by the excavation of soil. And the excavation of foundation pit will make the stress index of foundation pit change: the scope of application of various supporting structures are different, so we can not simply judge the quality of these supporting techniques. At the present stage, many construction units adopt this kind of support of steel pipe pile and bolt. Its main function is to reduce the displacement value of foundation pit. In the excavation of soil we should choose the support scheme reasonably according to the structure characteristics of soil layer and the technology owned by the construction unit and make the support scheme as diverse as possible. This can improve the stability of foundation pit.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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