岩溶地铁隧道地基承载力下限法研究

发布时间：2018-04-22 06:33

本文选题：岩溶 + 地铁　；参考：《中南大学》2014年硕士论文

【摘要】：摘要：随着我国人口增长和城镇化速度的加快,交通问题日益突出,地铁建设在全国各大城市先后展开。作为岩溶发育的主要物质基础,碳酸盐岩石在我国分布广泛,岩溶地质的存在成为地铁建设中不可忽略的一个问题。寻求一种计算地基承载力有效方法,对地铁安全施工和正常使用都有一定的指导意义。本文依托于国家(青年)自然科学基金资助项目“地铁隧道岩溶地基稳定性极限分析方法研究”(项目编号：51108462),主要的研究内容如下： (1)论述了极限分析方法尤其是求解下限解的一般原理,并对岩溶地基的提出简化模型,按铰接桁架法对其承载力进行了计算。 (2)阐述了下限有限元法的基本原理,并用MATLAB程序语言进行了编程,以MATLAB工具箱实现有限元法的线性规划求解。为验证此程序的适用性,先将其应用于条形基础地基承载力,将得到的结果与精确解进行比较。然后将其应用于地铁隧道岩溶地基承载力的计算,得出结论。 (3)采用ANSYS计算软件,选取合适的屈服准则,通过增量加载法,对地铁隧道岩溶地基承载力进行了研究。 (4)对隧洞底部存在单个溶洞的情况,利用上述两种方法探究地基承载力下限解与溶洞直径、顶板厚度等因素之间的关系规律。 (5)对隧洞底部存在串珠型溶洞的情况进行分析,结论表明自上而下第一个溶洞对极限承载力下限解起决定性作用。 (6)结合广州轨道交通工程沿线的岩溶地质报告,对存在多土层地质条件下的隧洞地基承载力进行了计算。
[Abstract]:Abstract: with the acceleration of population growth and urbanization in China, traffic problems become increasingly prominent. Subway construction has been carried out in all major cities in China. As the main material basis of karst development, carbonate rocks are widely distributed in China. The existence of karst geology has become a problem that can not be ignored in subway construction. To find an effective method to calculate the bearing capacity of foundation has certain guiding significance for the safe construction and normal use of subway. This paper is based on the National (Youth) Natural Science Foundation funded project "study on the limit Analysis method of the Karst Foundation Stability of Metro Tunnel" (Project No.: 51108462C). The main contents of the research are as follows: In this paper, the general principle of limit analysis method, especially the solution of lower limit, is discussed, and the simplified model of karst foundation is put forward, and the bearing capacity of karst foundation is calculated by hinge truss method. (2) the basic principle of the lower bound finite element method is expounded, and the linear programming solution of the finite element method is realized by MATLAB toolbox with MATLAB programming language. In order to verify the applicability of the program, it is first applied to the bearing capacity of strip foundation, and the obtained results are compared with the exact solution. Then it is applied to the calculation of the bearing capacity of underground tunnel karst foundation, and the conclusion is drawn. 3) the bearing capacity of karst foundation of subway tunnel is studied by means of incremental loading method and suitable yield criterion is selected by using ANSYS calculation software. 4) in the case of a single cave at the bottom of the tunnel, the relationship between the lower limit solution of the foundation bearing capacity and the factors such as the diameter of the cave and the thickness of the roof is studied by using the above two methods. The analysis of the existence of beaded caverns at the bottom of the tunnel shows that the first cave from top to bottom plays a decisive role in the solution of the lower limit of ultimate bearing capacity. Based on the karst geological report along Guangzhou rail transit project, the bearing capacity of tunnel foundation under multi-soil geological conditions is calculated.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U452.11

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