盾构法施工对邻近托换桩基影响的数值模拟分析

发布时间：2019-03-19 21:35

【摘要】：近几十年来，城市的发展正以前所未有的速度向前推进。作为城市交通最重要工具之一，地铁正在发挥越来越重要的作用。地铁的建设也在各大中城市的地下悄然铺开、遍布全城。如何在地铁施工时，，对上部建筑进行有效防护，一直是人们关注的重点。桩基托换技术正是对建筑物的桩基进行加固的工程措施之一，广泛运用在地铁施工时对上部建构筑物的防护中。因此针对地铁盾构法施工时桩基托换效果的研究具有十分重要的工程意义。本文首先简单介绍了隧道盾构法施工、桩基托换等关键工程技术，并在总结国内外的研究成果及现阶段研究中存在的不足的基础上，确定了利用大型有限元软件ANSYS对广州地铁六号线上某段桩基托换工程进行模拟分析的总体思路。具体的研究工作如下：（1）建立双桩梁式托换结构托换单桩的模型，比较隧道开挖前、开挖时、开挖后对托换桩基的水平变形、竖直变形、桩侧摩阻力以及轴力的影响作用（2）改变托换桩基之间的距离S、桩端位置、上部荷载作用位置以及注浆压力等工程参数，建立多种工况下的有限元分析模型。得到了各工程参数对托换桩基内力及变形的影响效果。（3）按具体工程方案建立双桩梁式托换结构托换多桩的模型。分析表明在采用桩基托换技术后，即使受到隧道盾构法施工的影响，桩基的内力及变形仍处于安全的范围内，进而验证了工程方案的合理性。
[Abstract]:In recent decades, the development of the city is advancing at an unprecedented rate. As one of the most important tools of urban transportation, subway is playing a more and more important role. Subway construction is also quietly spread in all large and medium-sized cities, spread all over the city. How to protect the upper building effectively during subway construction has always been the focus of people's attention. The pile foundation underpinning technology is one of the engineering measures to strengthen the pile foundation of the building, which is widely used in the protection of the upper structure in the subway construction. Therefore, it is of great engineering significance to study the underpinning effect of pile foundation in subway shield construction. In this paper, the tunnel shield method construction, pile foundation underpinning and other key engineering technologies are briefly introduced, and on the basis of summarizing the research results at home and abroad and the shortcomings existing in the present research, The general idea of simulating the pile foundation underpinning project on Guangzhou Metro Line 6 is determined by using the large-scale finite element software ANSYS. The concrete research work is as follows: (1) the model of double-pile beam-type underpinning single pile is established, and the horizontal deformation and vertical deformation of underpinning pile foundation before and after excavation are compared. The influence of side friction and axial force on pile (2) changing the distance of pile foundation, the position of pile end, the position of upper load and grouting pressure and other engineering parameters, the finite element analysis model under various working conditions is established. The effect of engineering parameters on the internal force and deformation of underpinning pile foundation is obtained. (3) according to the concrete project scheme, the model of double-pile beam-type underpinning structure is established. The analysis shows that the internal force and deformation of pile foundation are still in the safe range even if it is affected by tunnel shield construction after adopting pile foundation underpinning technology, and then the rationality of the project scheme is verified.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.43

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