【作者】 吴剑；

【导师】 仇文革；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2004， 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。然而，随着我国经济建设的蓬勃发展及西部大开发政策的进一步落实，对于交通基础设施建设特别是路网完善的需求在不断增加，大量冻土隧道的修建是不可避免的。因此，如何在冻土隧道的建设中采取行之有效的措施，避免或减轻冻害的发生，是目前隧道工程界急需解决的问题，开展冻土隧道冻害机理及相关防治技术的研究具有重大的工程实际意义和广阔的应用前景。 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，发现冻胀力是隧道冻害发生的主要原因，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。因此，在冻土隧道的研究中，最关键的问题就是研究冻土隧道的冻胀力。 目前从理论上计算冻土隧道冻胀力方法的研究走的是应力场、温度场、渗流场三场耦合分析的路，但由于工程实际情况的复杂性和数学力学方法的局限性，目前还处在非实用阶段，有很长的路要走。鉴于此，本文首先根据弹性力学理论推出了冻土隧道冻胀力计算公式。同时，根据弹塑性力学及有限元理论提出了冻土隧道冻胀力半理论半经验的计算方法，即以地温测试确定冻结圈范围、以原样力学测试确定冻结与非冻结状态围岩的物理力学参数为先导，而后进行自重应力场与温度应力场双场耦合的数值模拟分析的技术路线，利用大型有限元程序ANSYS实现了这种计算方法，并通过模型试验对其进行了验证。 根据冻胀力弹性力学计算方法，对不同冻结圈厚度、不同冻胀率情况下的冻土隧道冻胀力进行了计算和分析，得出了不同情况下的冻胀力——变形特征曲线和冻胀力变化规律。根据冻胀力弹塑性力学计算方法，利用大型有限元程序ANSYS建立平面应变问题的有限元模型，对不同埋深、不同冻结圈厚度、不同冻胀率情况下的冻土隧道冻胀力进行了计算和分析，得出了不同情况下的冻胀力——变形特征曲线和冻胀力分布规律。同时，对冻土隧道的深浅埋分界进行了初步探讨。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 transport service of railway and highway tunnel overseas and interiorly. Freeze injure endangers the safety of tunnel structure and transport service directly, causes serious economic loss. However, with vigorous development of economic construction and the policy of development in western part ascertained by degrees in our country, the requirement to basic transportation establishment adds, especially means of consummate transportation wet. Construction of large quantity tunnel in frozen earth can not be avoided. Therefore, how to take efficacious measure to avoid or reduce freeze injure in construction of tunnel in frozen earth is a problem that need to be settled urgently by tunnel workers at present. Carrying out study on principle of tunnel freeze injure and relative prevention and cure technology has major meaning of engineering practice and vast application foreground.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 discovered. Temperature, water, surrounding rock, engineering measure are main factors of tunnel freeze injure. Therefore, the key problem in study is frost force of tunnel in frozen earth.At present, the study on calculation method of frost force of tunnel in frozen earth use analysis method for the coupled problem of stress fields, temperature fields and seepage fields. Because of complexity of engineering practice and limitations of mathematics and mechanics method, this study is not practical. In view of this, calculation fomula of frost force of tunnel in frozen earth is put forward first in this paper according to elasticity mechanics theory. At the same time, half-theory and half-experience calculation method of frost force of tunnel in frozen earth is put forward according to elasticity-plasticity mechanics and finite unit theory. This calculation method is numeric analysis method for the coupled problem of deadweight stress fields and temperaturestress fields after determining scope of freezing surrounding rock by testing ground temperature and determining physics and mechanics parameter of freezing and not-freezing surrounding rock by original mechanics testing. This calculation method is realized by large-size finite unit program ANSYS and proved by model experiment.Frost force of tunnel in frozen earth is calculated and analyzed on condition of different scope of freezing surrounding rock and different rate of volume expansion of freezing surrounding rock according to calculation method of elasticity mechanics to frost force. The characteristic curve of frost force and deformation and the change law of frost force is put forward on different conditions. Finite unit model of plane-strain is set up by large-size finite unit program ANSYS according to calculation method of elasticity-plasticity mechanics to frost force. Frost force of tunnel in frozen earth is calculated and analyzed on condition of different installed depth, different scope of freezing surrounding rock and different rate of volume expansion of freezing surrounding rock. The characteristic curve of frost force and deformation and the distribution law of frost force is put forward on different conditions. At the same time, the dividing line of shallow tunnel and depth tunnel in frozen earth is discussed initially.更多还原