重庆南坪会展中心隧道穿越空箱挡墙的力学行为研究

发布时间：2018-02-27 06:11

本文关键词： 隧道穿越空箱挡墙数值模拟监控测量　出处：《重庆交通大学》2011年硕士论文　论文类型：学位论文

【摘要】：随着城市建设的不断发展,城市规模的不断扩大,隧道工程规划设计的难度越来越大,尤其在山区城市,隧道穿越既有建构筑物与人工回填土的情况已不可避免,并且与日俱增。其中涉及到的主要问题包括: ①人工回填土的隧道施工问题; ②隧道的超浅埋问题; ③隧道施工对周围既有建构筑物的影响问题; ④地表沉降问题。在城市复杂条件下,如何设计隧道才能将周围建构筑物的影响减小到容许范围之内,做到无坍塌,变形、沉降可控,爆破扰动小是目前城市隧道施工的一个研究重点,国内外研究越来越多。但是就目前研究现状来看,关于隧道穿越既有建构筑物时,既有结构的加固方案与隧道施工方案优化问题方面,仍然缺乏系统的研究成果。关于截取侵界结构物及其桩基的研究还不存在。因此,本文以重庆南坪下穿道隧道穿越空箱挡墙为背景,就空箱挡墙的加固方法、隧道进尺,以及截取挡墙桩基础的方法展开讨论。本文根分析了重庆南坪会展中心隧道穿越空箱挡墙所存在的潜在问题:空箱挡墙的开裂问题、倾斜问题、沉降问题、软弱回填土的滑塌问题、隧道的偏压问题、爆破振动的影响问题,地下水、地上生活废水以及地表降雨的防排问题。接着,针对上述问题,制定了相应的处理方案措施和方案,包括回填反压、挡墙内混凝土回填、各种减震措施、进尺调控超前管棚注浆、防排水管道与注浆止水、地表排水。本文选择了以上部分有代表性的方案措施,通过有限元三维非线性进行了挡墙墙内注浆分析、挡墙外侧反压回填土分析、进尺分析及截桩方式分析,并通过各工况进行了优劣评价,并筛选出最优工况。同时,本文用监控量测的方法检验了有限元分析的可靠性,分析了有限元分析与监控量测差异产生的原因。通过对南坪下穿道隧道穿越空箱挡墙的研究,本文得出了以下结论: ①对空箱挡墙加固处理可减少隧道施工对空箱挡墙稳定性的影响。其中挡墙的加固措施包括: 1)向空箱挡墙箱内注浆以增加挡墙自重; 2)向挡墙背后回填人工回填土以维持其力学平衡; ②进尺控制可限制隧道开挖对空箱挡墙稳定性的影响; ③截桩时分两步截取可减少截桩对挡墙稳定性的影响; ④通过将有限元分析与监控量测的结果进行比对,验证了有限元分析方法的正确性。
[Abstract]:With the development of urban construction and the expansion of city scale, the planning and design of tunnel engineering is becoming more and more difficult. Especially in mountainous cities, it is inevitable that the tunnel passes through the existing structures and artificial backfill. The main issues involved include:. (1) tunnel construction of artificial backfill; (2) the problem of super-shallow buried tunnel; (3) the influence of tunnel construction on the surrounding existing structures; 4. Surface subsidence. Under complex urban conditions, how to design tunnels to reduce the influence of surrounding structures to the allowable range, to achieve no collapse, deformation, settlement controllable, small blasting disturbance is one of the current urban tunnel construction research focus. There are more and more researches at home and abroad. However, as far as the present research situation is concerned, the reinforcement scheme of the existing structure and the optimization of the tunnel construction plan when the tunnel passes through the existing building structure, There is still a lack of systematic research results. There is no research on intercepting intrusive structure and its pile foundation. Therefore, this paper takes the underpass tunnel of Nanping in Chongqing as the background, and discusses the reinforcement method of empty box retaining wall and the tunnel ruler. And the method of intercepting retaining wall pile foundation is discussed. This paper analyzes the potential problems existing in the tunnel of Nanping Convention and Exhibition Center in Chongqing through the empty box retaining wall, such as cracking of empty box retaining wall, slanting problem, settlement problem, collapse of soft backfill soil, bias pressure of tunnel, etc. The impact of blasting vibration, groundwater, domestic waste water above ground and surface rain prevention problem. Then, in view of the above problems, the corresponding treatment measures and schemes, including backfill back pressure, concrete backfill in the retaining wall, All kinds of earthquake absorption measures, grouting in advance pipe shed, waterproofing pipe and grouting, surface drainage. In this paper, some representative schemes are selected, and the grouting analysis in the retaining wall is carried out by means of 3D nonlinear finite element method. The analysis of backfill on the outer side of the retaining wall, the advance analysis and the analysis of the method of cutting pile are carried out, and the advantages and disadvantages of each condition are evaluated, and the optimum condition is screened out. At the same time, the reliability of the finite element analysis is tested by the method of monitoring and measuring. The causes of the difference between finite element analysis and monitoring measurement are analyzed. Based on the research of the tunnel passing through the empty box retaining wall, the following conclusions are drawn in this paper:. 1 strengthening the empty box retaining wall can reduce the influence of tunnel construction on the stability of the empty box retaining wall. The reinforcement measures of the retaining wall include:. 1) grouting into the empty box to increase the weight of the retaining wall; 2) backfilling the artificial backfill to the back of the retaining wall to maintain its mechanical balance; (2) the influence of tunnel excavation on the stability of empty box retaining wall can be restricted by feeding rule control; (3) the influence of the truncated pile on the stability of retaining wall can be reduced by two steps interception of the truncated pile; 4. By comparing the results of finite element analysis and monitoring measurement, the correctness of finite element analysis method is verified.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：U451

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