深基坑“支—围护单一墙”顺作法施工过程中力学响应的数值分析

发布时间：2018-10-12 12:49

【摘要】：随着我国经济的发展和城市化进程的推进,超高层建筑和地下工程与日俱增,深基坑工程也随之越来越多,而土地资源的匮乏迫使我们要更加合理的利用地下空间,这就不得不对建筑物基坑工程提出了更高的要求。“两墙合一”地下连续墙因其在控制变形、缩短工期、可持续发展方面的诸多优点而被广泛采用。论文以“两墙合一”地下连续墙结合内支撑支护结构的某深基坑工程实例为背景,采用弹性抗力法计算与数值模拟相结合的方法开展研究。利用ABAQUS大型有限元软件建立了顺作法施工过程一体化的有限元模型,对土体、围护结构以及周边环境进行二维数值分析,论文主要进行了以下几个方面的工作:(1)论文利用理正深基坑软件中的增量法对开挖过程进行了分析计算,得到了开挖过程中地下连续墙的内力和变形情况,并对基坑周围土体沉降做了预测。(2)对“两墙合一”地下连续墙的水平位移,土体的水平位移,坑底隆起以及坑外地表沉降等变形进行了系统的分析。将连续墙的水平位移与实际监测结果进行了对比,说明在参数选择合适的情况下可利用ABAQUS二维数值模拟进行预测。(3)应用ABAQUS有限元软件进行主要相关参数分析,分别对地下连续墙的厚度、内支撑刚度、土体的参数(内摩擦角、粘聚力)等影响因素进行研究,分析其对“两墙合一”地下连续墙侧移的影响。分析表明通过增加地下连续墙厚度对墙体变形具有一定的控制作用,但增大到一定范围时,对墙体变形影响不大。地下连续墙的水平位移随着内支撑刚度地增加而减小,且减小的幅度逐渐降低,当刚度增大超过一定的范围,对墙体变形影响不明显。通过对建模过程中土体的粘聚力和内摩擦角的改变,发现增大内摩擦角和粘聚力可以很好的控制基坑变形,且内摩擦角对墙体变形影响更大。
[Abstract]:With the development of our country's economy and the advancement of urbanization, the super high-rise building and underground engineering are increasing day by day, and the deep foundation pit engineering is also more and more, and the scarcity of land resources forces us to make more reasonable use of underground space. This has to put forward a higher request to the foundation pit engineering of the building. "two walls in one" underground continuous wall is widely used because of its advantages in controlling deformation, shortening construction period and sustainable development. Based on the example of a deep foundation pit project with "two walls in one" underground continuous wall combined with internal bracing structure, the method of elastic resistance method and numerical simulation is used to carry out the research in this paper. In this paper, the finite element model of the construction process is established by using the ABAQUS software, and the soil mass, the enclosure structure and the surrounding environment are analyzed by two-dimensional numerical method. The main work of this paper is as follows: (1) the paper analyzes and calculates the excavation process by using the incremental method in the software of Lizheng Deep Foundation Pit, and obtains the internal force and deformation of the underground continuous wall during the excavation. The settlement of soil around the foundation pit is predicted. (2) the horizontal displacement, the horizontal displacement of the soil, the uplift of the bottom and the settlement of the surface of the pit are systematically analyzed. The horizontal displacement of the diaphragm wall is compared with the actual monitoring results, which shows that the ABAQUS two-dimensional numerical simulation can be used to predict the parameters when the parameters are suitable. (3) the main related parameters are analyzed by using the ABAQUS finite element software. The influence factors such as the thickness of underground diaphragm wall, the stiffness of internal support and the parameters of soil (internal friction angle, cohesive force) are studied, and the influence of these factors on the lateral displacement of underground continuous wall with "two walls in one" is analyzed. The analysis shows that the wall deformation can be controlled by increasing the thickness of diaphragm wall, but when it is increased to a certain range, it has little effect on the wall deformation. The horizontal displacement of the diaphragm wall decreases with the increase of the stiffness of the inner bracing, and decreases gradually. When the stiffness increases beyond a certain range, the influence on the wall deformation is not obvious. By changing the cohesive force and internal friction angle of soil in the process of modeling, it is found that increasing the internal friction angle and cohesion force can control the deformation of foundation pit well, and the internal friction angle has more influence on the wall deformation.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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