土壤隧道挖掘和深基坑开挖有限元仿真

发布时间：2018-05-07 23:15

本文选题：单隧道 + 双隧道　；参考：《西华大学》2014年硕士论文

【摘要】：随着现代科学技术的发展，社会经济的迅速前进，推动着整个城市发展的日新月异。在城市快速的发展过程中，出现了城市人口与城市空间之间的矛盾。为了解决城市土地紧张的问题，，所以合理有效的开发和利用城市地下空间，不仅可以缓解这种矛盾而且也可满足社会发展的特殊需求。但我们在进行地下空间利用的时候，往往会带来地表沉降、城市旧居拆迁、土方开挖（明挖或暗挖）、基槽开挖边坡支护等岩土工程方面问题。随着城市化进程越来越快，如何在高密度的建筑下对地下空间进行合理的开发和利用成为城市现代化进程中不可忽视的问题。本文就是利用COMSOL Multiphysics有限元分析软件对岩土工程中隧道挖掘和深度开挖过程这两个方面进行了分析和研究。对于隧道开挖从三个方面进行了研究和分析，第一是土壤单隧道的分析，分析过程中并没涉及到地表建筑物对其产生的影响；第二是通过建筑物对隧道挖掘过程中产生的影响以及隧道中心和地面距离之间的关系；第三是通过对双隧道间的相互作用进行了分析，模拟了两条隧道并排式和背负式两种挖掘方式之间的关系和影响。对于深基坑开挖过程，分析了在开挖过程引起的土体位移的变化，这种分析对深基坑的设计，保证施工的安全有着积极的意义。通过对所建理论模型的研究，本文认为：在对单隧道的挖掘过程中，随着地表建筑的重力逐渐增大，地面产生出的水平位移和垂直位移都是一个增大的过程，并且对所挖隧道周围产生的应变范围逐渐减小；随着隧道中心离地面的距离逐渐增大，可以明显的降低水平位移和垂直位移，这样对我们在实际挖掘中选择合适的挖掘深度，起着重要的意义；对于并排式双隧道挖掘过程中，随着两隧道的中心距逐渐增大，垂直位移呈现出逐渐减小的过程，而水平位移并没有产生出明显的变化，应变范围随着它们距离的增大而减小；对于背负式双隧道的开挖过程中，随着两隧道的中心距逐渐增大，水平位移和垂直位移并没有出现明显的变化，而应变范围随着它们距离的增大而减小。对于基坑开挖过程，基坑从整体上来讲是稳定的，基坑的最大变形是发生在顶部，随着开挖深度的不断增加，总位移变化趋势是不断增加的过程，当开挖到基坑底时，位移增加速率有所减缓，基坑基本趋于稳定。对于隧道和深基坑开挖这两方面的研究，都是为了找到一种影响范围最小的开挖方式，这在实际工况中起着重要的意义。
[Abstract]:With the development of modern science and technology and the rapid progress of social economy, the development of the whole city is advancing with each passing day. In the rapid development of the city, there is a contradiction between urban population and urban space. In order to solve the problem of urban land tension, the reasonable and effective development and utilization of urban underground space can not only alleviate this contradiction but also meet the special needs of social development. However, when we make use of underground space, we often bring geotechnical engineering problems such as ground subsidence, urban old house demolition, earthwork excavation (open or hidden excavation), foundation trench excavation, slope support and other geotechnical engineering problems. With the process of urbanization becoming faster and faster, how to develop and utilize underground space in high density buildings has become a problem that can not be ignored in the process of urban modernization. In this paper, two aspects of tunnel excavation and deep excavation in geotechnical engineering are analyzed and studied by using COMSOL Multiphysics finite element analysis software. The tunnel excavation is studied and analyzed from three aspects. The first is the analysis of single soil tunnel, which does not involve the influence of surface buildings on the tunnel excavation. The second is the influence of the building on the tunnel excavation and the relationship between the tunnel center and the ground distance. The third is the analysis of the interaction between the two tunnels. The relationship and influence between two tunneling methods, side-by-side and backpack, are simulated. For the process of deep foundation pit excavation, the variation of soil displacement caused by excavation process is analyzed, which is of positive significance to the design of deep foundation pit and the safety of construction. Through the study of the theoretical model, this paper holds that the horizontal and vertical displacement generated by the ground is an increasing process in the excavation process of a single tunnel with the increasing gravity of the surface building. With the increasing distance from the tunnel center to the ground, the horizontal displacement and vertical displacement can be obviously reduced, so we can choose the appropriate excavation depth in the actual excavation. The vertical displacement decreases gradually with the increasing of the center distance of the two tunnels, but the horizontal displacement does not produce obvious change. The strain range decreases with the increase of their distance, while the horizontal displacement and vertical displacement do not change obviously with the increasing of the center distance between the two tunnels during the excavation of the backpack double tunnel. The strain range decreases with the increase of their distance. For the excavation process of foundation pit, the foundation pit is stable on the whole, and the maximum deformation of foundation pit occurs at the top. With the increasing of excavation depth, the total displacement change trend is increasing, when excavation to the bottom of foundation pit, The increasing rate of displacement has slowed down, and the foundation pit tends to be stable. The study of tunnel and deep foundation pit excavation is to find a kind of excavation method with the smallest influence range, which plays an important role in the actual working conditions.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455;TU753.1

【参考文献】