【作者】 丁敏；

【导师】 王成；

【作者基本信息】 重庆交通大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 国内外大量铁路、公路隧道建设和运营的实践证明,在高纬度或高海拔的寒冷地区,尤其是多年冻土地区,加之地下水比较发育时,隧道常常会发生冻害,直接威胁到隧道结构及运营行车的安全,造成严重的经济损失。本文以鄂西地区沙子垭隧道为背景,在对大量冻土隧道冻害现象及其形成机理进行研究的基础上,发现温度条件、水文条件、围岩条件、工程措施是隧道冻害发生的主要因素。论文密切结合实际工程,采用理论分析与现场实测相结合的研究方法进行季节性冻土隧道计算理论和冻害防治技术等多方面的研究。①运用传热学和冻土学的基本理论,考虑水份场和温度场的耦合影响,推导出了水份场和温度场耦合问题的二维控制微分方程,应用Galerkin法得了数值解法。运用ANSYS软件,进行了沙子垭隧道水份场和温度场耦合问题的二维非线性分析。②水份场对季节性冻土隧道的温度场的影响较大,在设计时应该考虑水份场与温度场的耦合影响;当沙子垭隧道洞口段的初期支护和二次衬砌之间铺设了导热系数λ为0.03 W (m ?°C)、厚度d为8.0cm的保温材料后,可以保证沙子垭隧道洞口段围岩很小范围内出现冻结。③根据传热学和有限元的基本理论,考虑应力场和温度场的耦合影响,建立了应力场和温度场耦合问题的二维数学模型,并应用Galerkin法进行了有限元分析。分析结果表明:温度场对季节性冻土隧道的应力场影响较大,在设计时应该考虑应力场与温度场的耦合影响。更多还原

【Abstract】 In high latitude or high elevation cold region, especially means of many years frozen earth region, freeze injure always happens in tunnel when ground water grows. Thus is proved by a lot of practice of construction and transportservice of railway and highway tunnel overseas and interiorly. Freeze injure endangers the safety of tunnel structure and transport service directly, causes serious economic loss.Aimed the shaziya tunnel in Hubei Province as an example and on base of study on large quantity phenomena and principle of tunnel freeze injure, that frost force is main reason of tunnel freeze injure is temperature, water, surrounding rock, engineering measure are main factors of tunnel freeze injure. This paper connects tightly with the real engineering. Using the research method combined the theoretical computational analysis with the field observation; the researches on the theoretical computational analysis of the seasonally frozen soil tunnel, the technology of constructing and preventing the damage of the seasonally frozen soil tunnel have been investigated. The research results can provide the theoretical help and reference for the constructing and the damage of the seasonally frozen soil tunnel. The following research work has been done in detail.According to the essential theories of geocryology and heat transfer, taking the coupled effects of the moisture field and the temperature field into account, two-dimensional governing differential equations of the couple problem are presented, the finite element formulae of this problem are obtained by Galerkin’s method, and the computer program of the finite element is compiled. Using ANSYS software, two-dimensional nonlinear analysis for the coupled problem of the moisture field and the temperature field in Shaziya tunnel are worked out.On the one the hand, the results show that the effect of the moisture field on temperature field in the tunnel in the seasonally frozen soil tunnel is very great, and that the moisture field should be taken into account during the design. On the other hand, the results show, if the insulation material, whose conduction coefficientλis 0.03 W ( m ?°C ) and width d is 8.0 cm, is fitted with tunnel, the rock surrounding the entrance of tunnel will occur litter part frozen earth.According to the essential theories of heat transfer and finite element, considering the coupled effects of the stress field and temperature field, two-dimensional computational model of the coupled problem are given, the finite element formulae of this problem are obtained by Galerkin’s method. The results show that the effect of the temperature filed on the stress field in the seasonally frozen soil tunnel is very great, and the stress field should be taken into account during the design.更多还原