【作者】 蒋武军；

【导师】 葛修润；

【作者基本信息】 中国科学院研究生院（武汉岩土力学研究所） ， 岩土工程， 2005， 博士

【摘要】 透壁式通风管路基是一种全新的冷区工程措施。本文主要研究了透壁式通风管路基的非线性温度特性,主要内容如下:1.本文介绍透壁式通风路基的降温机理:利用青藏高原年平均气温为负值、大气气温一般比地表温度低三度以上、以及风力资源较丰富的特点,通过空气在路基介质中流动带走堤身热量而达到主动降低路基下地温目的。与传统的通风路基有着本质区别。2.提出了透壁式通风路基的理论模型:利用Brinkman模型处理纯流体空气区域与多孔介质区域的耦合流动;在局部非热平衡理论的基础上把多孔介质骨架和流体分别看成两种不同的连续介质,在任意点和其相应的特征体积单元REV内分别定义两个平均温度,即固相平均温度Ts和流体相平均温度Tf,它们分别表征了同一特征单元每相的热状态,把多孔结构内的传热视为两相之间的传热;利用序贯耦合交错求解的方法求解流固耦合的“双能量方程”。3.利用Heaviside函数的阶梯性及Gaussian函数的突变性模拟了冻土相变过程能量的突变,提高了数值求解收敛的速度和稳定性。4.在两种气候条件下对透壁式通风路基、普通通风路基及普通非通风路基进行了对比模拟研究,得出透壁通风路基与普通通风路基是积极主动调控地温的冷区工程措施,其中透壁式通风路基的降温效果更好;非通风普通路基是一种消极保护多年冻土的工程,且路基下冻土有退化现象。5.在透壁式通风路基模型的基础上提出了片石气冷路基的控制模型,并进行了数值模拟分析,得出片石气冷路基能提高冻土上限,达到保护冻土的作用。更多还原

【Abstract】 The ventilated embankment with porous ventilated tubes inside is a bran-new engineering measure, whose nonlinear temperature characteristic was studied in this paper.1. Refrigeration mechanism of ventilated embankment with porous tubes inside was presented, which is that air cool embankment by heat convection inside embankment medium under conditions of low temperature and windy weather, and is different from common ventilated embankment in nature.2. The theory model of ventilated embankment with porous tubes inside was presented. Coupling problem between fluid and solid was solved by Brinkman model in the region of porous media; Fluid and porous medium were looked as two kinds of different continuous media, and on the basis of local non-thermal equilibrium theory average temperature of solid phase and gas phase was defined in REV; Heat transfer in porous medium was looked as the exchange of heat between solid phase and gas phase; Double energy equations were solved by means of sequential coupling.3. The phase change phenomena of frozen soil were simulated based on Characteristics of Heaviside staircase function and Gaussian jump function, and convergence and stability were improved.4. The temperature characteristics of the ventilated embankment with porous ventilated tubes inside, common ventilated embankment and common embankment were simulated under two different climatic conditions, and the calculated results indicate that two kinds of ventilated embankments heighten the upper limit of frozen soil. The better one is the ventilated embankment with porous ventilated tubes inside.5. Governing differential equations of ballast embankment were presented and modeled based on the model of the ventilated embankment with a porous ventilated tube inside. The calculated results indicate that ballast embankment can heighten the upper limit of frozen soil to protect the frozen soil.更多还原