严寒地区铁路隧道温度场变化规律及冻害防治技术研究

发布时间：2019-02-11 21:09

【摘要】：随着我国基础设施建设的快速发展,交通工程中严寒地区隧道数量日益增多,寒区隧道病害也日渐突出,已成为工程界所关注的又一难点问题。近20年来,各国学者虽然对寒区隧道温度场分布规律及冻害防治技术等进行了较为系统的研究,也提出了很多具有实用价值的理论与方法,为寒区隧道抗防冻设计与施工提供了依据。但由于隧道所处地理位置、工程地质条件、复杂环境以及施工技术水平的影响,仍然存在很多问题值得进一步研究。因此,本文以高纬度严寒地区后安山隧道为研究背景,选取试验段,采用文献查阅、现场监测、数值模拟、现场实践总结等手段,从寒区隧道温度场分布规律、隧道防排水冻害防治技术、初期支护冻害预防和治理等三个方面开展系统研究,取得了以下主要研究成果和结论:(1)通过对后安山隧道典型断面布设温度计,掌握了施工过程中和隧道贯通后围岩温度场和隧道纵向温度场分布规律,为避免冻害提供了理论指导。测试结果表明,保温板两侧温度相差最大9.21℃,可以起到很好的保温效果,在距洞门200 m范围内铺设5 cm厚的保温板仍有可能产生冻害。以后安山隧道为研究依托,采用ABAQUS有限元建立计算模型,讨论了隧道贯通前后保温层厚度对温度场的影响和保温设防段长度。通过数值模拟得出隧道贯通后的保温设防段长度为720~830 m。(2)为了得出中心深埋水沟的防排水效果,从中心深埋水沟路基出口开始布设悬挂式温度湿度计,共计布设8点,布置于侧壁。经过一年多的测试,得出中心水沟内温度场分布规律。并借助于有限元软件ABAQUS,研究了水沟埋深与冻结深度的关系,研究结果表明,设计中水沟埋深轨下3.7 m,除了出口位置,完全可以防止发生冻结现象。(3)针对初期支护容易损伤劣化的现象,以后安山隧道为背景,首先分析了初期支护的破坏机理,然后对季节性冻土隧道的温度场进行调查分析的基础上说明了对支护采取防冻措施的必要性,重点对后安山隧道在洞门口采取防寒门的防冻效果进行了分析,结果表明设置防寒门后进洞50 m温度就转成正温。最后从采用耐低温喷射混凝土技术、设置防寒保温门和空气幕、围岩注浆堵水、火炉加热和电加热法四个方面对初期支护的防护措施进行了总结。
[Abstract]:With the rapid development of infrastructure construction in our country, the number of tunnels in severe cold areas in traffic engineering is increasing day by day, and the tunnel diseases in cold regions are becoming more and more prominent, which has become another difficult problem that the engineering circles pay attention to. In the past 20 years, scholars from all over the world have made a systematic study on the distribution of tunnel temperature field and freezing damage prevention techniques in cold regions, and have also put forward many theories and methods with practical value. It provides the basis for the design and construction of anti-freezing tunnel in cold area. However, due to the influence of the location of the tunnel, the engineering geological conditions, the complex environment and the level of construction technology, there are still many problems worthy of further study. Therefore, based on the research background of Houanshan Tunnel in high latitude and severe cold area, this paper selects the experimental section, adopts the methods of literature reference, field monitoring, numerical simulation, field practice summary, and so on, from the distribution law of tunnel temperature field in cold region. In this paper, three aspects of prevention and control technology of tunnel anti-drainage and freezing damage, prevention and treatment of initial support freezing damage are carried out. The main research results and conclusions are as follows: (1) through setting up thermometers on typical sections of Houanshan Tunnel, The distribution law of surrounding rock temperature field and tunnel longitudinal temperature field in the construction process and after the tunnel is through is grasped, which provides theoretical guidance for avoiding freezing damage. The test results show that the maximum temperature difference on both sides of the insulation board is 9.21 鈩，

本文编号：2420109