冻土隧道冻胀力敏感度分析及防冻保温技术研究

发布时间：2018-03-27 15:30

本文选题：冻土隧道　切入点：冻胀力　出处：《重庆交通大学》2014年硕士论文

【摘要】：随着我国经济建设的发展，西部大开发政策的实施，交通基础设施建设的需求在不断增长，尤其是我国藏区高原铁路、公路建设的兴起，高海拔寒冷地区冻土隧道的建设技术问题日益受到工程界的关注和重视。公路隧道—工程建设中的重要结构物，迎来了空前规模的建设热潮。隧道围岩中的裂隙水和孔隙水冻结时，围岩发生体积膨胀，当体积膨胀受到冻土隧道衬砌和未冻围岩体的约束，冻结围岩对冻土隧道衬砌产生作用力，冻土隧道衬砌对冻结围岩产生抗力，约束其体积膨胀，这就形成围岩冻胀力。隧道衬砌受冻胀力与其他的作用力共同作用，可能造成隧底冒水、积冰、冻胀，使隧道衬砌开裂、酥碎、剥落，导致隧道出现漏水、结冰、挂冰等一系列冻害，威胁隧道的正常运营。冻土区隧道工程作为一个重要研究课题列入研究计划中，因为冻土区隧道工程有其特殊性，一方面反映非冻土区所没有的特点与问题，另一方面与非冻土区在一些问题虽具有共性，，但在冻土区中反映更为清晰和透彻，因此冻土区隧道工程问题早己引起冻土区国家工程界的普遍重视，引起国家工程界科研人士的研究热潮。冻土区隧道工程面临的主要挑战有：①隧道衬砌层将遭受冻胀力的作用。②冻土区隧道围岩与衬砌要遭受反复的冻融作用，形成各种冻害。冻土隧道冻害的问题以前就己经大量发生，也是长期以来隧道工程界研究的重点课题。对于隧道冻胀力进入深入研究，其中衬砌冻胀力是最为重要的研究内容，确定冻胀力的影响因素，冻胀力的计算方法，进行冻胀力的敏感度分析，研究围岩的冻胀机理，对由冻胀力产生的冻害采取措施防止，探求隧道建设中的一些保温防冻措施和工程实际措施。本论文的主要研究工作如下： ①调查冻土隧道的冻害现象及研究冻土冻胀的力学机理 ②通过实测实际工程隧道建设中的围岩温度，然后进行整理和分析，得出隧道围岩冻融圈的范围。 ③以冻融岩石圈整体冻胀说为理论基础和实测冻融圈的范围为参考，通过弹性力学和弹塑性有限元数值模拟的方法，研究冻胀力及冻胀应力的影响因素，研究冻胀应力在隧道衬砌的分布规律； ④研究和总结防冻保温技术在实际工程中的应用。
[Abstract]:With the development of China's economic construction and the implementation of the policy of developing the western region, the demand for the construction of transportation infrastructure is constantly increasing, especially the rise of plateau railway and highway construction in the Tibetan region of China. More and more attention has been paid to the construction technology of frozen earth tunnel in the cold area at high altitude. When the fissure water and pore water in the surrounding rock of the tunnel are frozen, the volume expansion of the surrounding rock occurs, and when the volume expansion is restricted by the tunnel lining and the unfrozen surrounding rock body, the volume expansion of the surrounding rock is restricted by the frozen soil tunnel lining and the unfrozen surrounding rock body. The frozen wall rock exerts force on the tunnel lining of frozen soil, and the tunnel lining of frozen soil produces resistance to the frozen surrounding rock and restricts its volume expansion, which forms the frost heave force of surrounding rock. The combined action of frost heaving force on tunnel lining and other forces may result in water rising, ice accumulation, frost heaving at the bottom of the tunnel, cracking, crumbling and spalling of the tunnel lining, resulting in a series of freezing damage such as leakage, icing and ice hanging in the tunnel. As an important research topic, tunnel engineering in frozen earth region is included in the research plan, because tunnel engineering in frozen earth region has its particularity, on the one hand, it reflects the characteristics and problems that do not exist in non-frozen soil region. On the other hand, although there are some common problems with non-frozen soil regions, they are reflected more clearly and thoroughly in frozen soil regions. Therefore, the tunnel engineering problems in frozen soil regions have long attracted the general attention of the national engineering circles in frozen earth regions. The main challenge of tunnel engineering in frozen soil region is that the lining of tunnel will be subjected to frost heave force. 2. the wall rock and lining of tunnel in frozen soil region will be subjected to repeated freezing and thawing. The problem of freezing injury in frozen soil tunnel has occurred in large quantities before, and it has been a key topic in tunnel engineering for a long time. The frost heave force of tunnel has entered deep research, among which the frost heave force of lining is the most important research content. The influence factors of frost heave force, the calculation method of frost heave force, the sensitivity analysis of frost heave force, the frost heave mechanism of surrounding rock are studied, and the measures to prevent the frost damage caused by frost heaving force are taken. To explore some heat preservation and anti-freezing measures and practical engineering measures in tunnel construction. The main research work of this thesis is as follows:. 1. Investigation of freezing damage phenomenon in frozen soil tunnel and study on mechanics mechanism of frost heave in frozen soil. (2) by measuring the surrounding rock temperature in the tunnel construction, and then arranging and analyzing, the range of the freeze-thaw circle of the tunnel surrounding rock is obtained. (3) based on the theory of frozen-thawing lithosphere and the range of frozen-thawing circle, the influence factors of frost heave force and frost heave stress are studied by means of elastic mechanics and elastic-plastic finite element numerical simulation method. The distribution of frost heave stress in tunnel lining is studied. 4 study and summarize the application of anti-freezing and heat preservation technology in practical engineering.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451.2

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