寒区铁路隧道冻害机理及整治技术研究

发布时间：2018-04-22 09:22

本文选题：寒区隧道 + 冻胀力　；参考：《中国铁道科学研究院》2015年硕士论文

【摘要】：严寒地区铁路隧道冻害现象普遍存在,影响了结构的使用性能,是困扰工程界的热点和难点问题。论文针对寒区隧道冻害问题,依托栗家湾二号、军都山等既有铁路隧道,围绕隧道冻害机理及整治技术,通过现场调研、理论分析和数值模拟,分析了冻害的成因及影响因素,研究了冻胀力对围岩和衬砌结构影响破坏、隧道温度场的分布等,提出了新型的冻害整治措施。主要研究内容如下:(1)分析了隧道冻害现象及影响因素。隧道常见冻害形式是衬砌渗漏水、挂冰、冻胀开裂,基底翻浆冒泥、冻胀隆起,洞门墙开裂,洞口处热融滑塌,排水系统冻结堵塞等,从温度、水、围岩和设计施工缺陷等角度分析了冻害产生的影响因素,研究了围岩和衬砌混凝土在冻融循环作用下的冻胀劣化特性。(2)研究了衬砌结构的冻害机理。寒区隧道结构开裂与水冻结成冰时体积膨胀产生的冻胀力有关,采用均匀孔隙含水围岩和等厚度冻结含水层围岩的冻胀模型计算冻胀力,当冻胀力作用于衬砌结构超过混凝土的抗拉、抗剪、抗压强度时,会使衬砌产生张裂、错台和压溃等破坏。(3)研究了隧道温度场的分布规律。通过有限元软件模拟了以栗家湾二号隧道为例的温度场分布特征,即三维空间冻结面沿隧道纵向大致呈喇叭口形分布,并得出施加5cm硬质聚氨酯保温层可减缓冻结圈的发展,减小围岩的冻结深度。(4)提出了寒区铁路隧道冻害的新型整治措施。冻害整治措施应以治水为主,兼顾保温、加固围岩及衬砌、提高设计和施工质量,采取“电伴热带+保温层+排水盲管+橡胶波纹板”的综合治水方案可有效治理衬砌渗漏水挂冰病害;隧道基底锚注一体化的新型整治措施可有效的改善围岩受力状况,提高地基承载力。
[Abstract]:The freezing damage of railway tunnel in severe cold area is a hot and difficult problem which affects the performance of the structure and puzzles the engineering field. Based on the existing railway tunnels such as Lijiawan No. 2 and Jundushan, the paper analyzes the causes and influencing factors of freezing injury through field investigation, theoretical analysis and numerical simulation. The influence of frost heaving force on surrounding rock and lining structure and the distribution of tunnel temperature field are studied. The main research contents are as follows: (1) the phenomenon of tunnel freezing injury and its influencing factors are analyzed. The common forms of frost damage in tunnels are lining leakage, ice hanging, frost heaving cracking, foundation mud pouring, frost heaving, door wall cracking, thermal thawing collapse at the opening of the tunnel, freezing and plugging of drainage system, etc., from temperature, water, etc. The influence factors of frost damage are analyzed from the angles of surrounding rock and design and construction defects. The frost heave deterioration characteristics of surrounding rock and lining concrete under the action of freeze-thaw cycle are studied. (2) the frost damage mechanism of lining structure is studied. The cracking of tunnel structure in cold region is related to the frost heaving force caused by volume expansion when water freezes. The frost heave force is calculated by using the frost heave model of uniform pore water bearing surrounding rock and freezing aquifer surrounding rock of equal thickness. When the frost heave force acts on the lining structure beyond the tensile, shear and compressive strength of concrete, it will cause the lining to produce tensile cracks, staggered platforms and collapses, etc.) the distribution of the tunnel temperature field is studied. The temperature field distribution characteristics of Lijiawan No. 2 Tunnel are simulated by finite element software, that is, the three-dimensional frozen surface is approximately bell-shaped along the longitudinal direction of the tunnel, and it is concluded that the application of 5cm rigid polyurethane insulation layer can slow down the development of the freezing circle. To reduce the freezing depth of surrounding rock, this paper puts forward a new regulation measure for freezing damage of railway tunnel in cold area. Freezing damage treatment measures should focus on water control, take into account heat preservation, reinforce surrounding rock and lining, and improve the quality of design and construction. Adopting the comprehensive water control scheme of "electric insulation layer drainage blind pipe rubber corrugated plate" can effectively control the water leakage and ice hanging disease of lining, and the new regulation measures of the integration of anchor and grouting on the base of tunnel can effectively improve the stress condition of surrounding rock. Increase the bearing capacity of the foundation.
【学位授予单位】：中国铁道科学研究院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U457

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