多年冻土区高等级公路特殊路基长期降温效果研究

发布时间：2018-04-24 12:08

本文选题：渗透率 + 惯性阻力系数　；参考：《冰川冻土》2014年04期

【摘要】：气候变暖背景下,块石路基及通风管-封闭块石基底复合路基成为多年冻土区高等级公路冷却路基的主要结构形式.为探明不同直径块石层的渗流特征和规律,开展了立方排列球体室内风洞试验,一方面获得了渗透率和惯性阻力系数及其与球体直径间的统计关系;另一方面得到了球体层内部压力梯度与渗流速度呈二次非线性关系.基于该试验得到的参数和关系,采用多孔介质中流固耦合传热模型,通过有限体积法模拟了柴木铁路块石路基的降温效果,并利用实测数据验证了模型及参数的可靠性.在此基础之上,以青藏高等级公路特殊路基为原型,使用该传热模型开展了封闭块石基底路基和通风管-块石复合路基长期冷却降温效果的数值模拟研究.结果表明:封闭块石基底路基和通风管-封闭块石复合路基在研究期内均有降温效果,可以提高路基下人为上限,而块石夹层路基在一定时期内可以提高冻土上限,但下部土体温度升高,长期降温效果较差.
[Abstract]:Under the background of climate warming, rock block subgrade and ventilation tube-block rock base composite subgrade have become the main structural forms of high grade highway cooling subgrade in permafrost region. In order to find out the percolation characteristics and rules of different diameter block rock beds, the indoor wind tunnel test of cubic spherical array was carried out. On the one hand, the permeability, inertia resistance coefficient and the statistical relationship between permeability and spherical diameter were obtained. On the other hand, the quadratic nonlinear relationship between the pressure gradient and the seepage velocity is obtained. Based on the parameters and relationships obtained from the experiment, the fluid-solid coupled heat transfer model in porous media is used to simulate the cooling effect of block rock subgrade of Qaimu railway by finite volume method, and the reliability of the model and parameters is verified by the measured data. On this basis, the numerical simulation of the cooling and cooling effect of the closed rock base subgrade and the ventilation tube-block composite subgrade is carried out with the special subgrade of Qinghai-Xizang high grade highway as the prototype and the heat transfer model is used to study the long-term cooling and cooling effect of the roadbed. The results show that both the closed stone base subgrade and the ventilation tube-block block composite subgrade have cooling effect during the study period, which can increase the artificial upper limit of the roadbed, while the upper limit of the frozen soil can be increased in a certain period of time. But the lower soil temperature increases, the long-term cooling effect is poor.
【作者单位】：甘肃省交通科学研究院有限公司;中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室;中交第二公路工程局有限公司;天津市地下铁道集团有限公司;
【基金】：冻土工程国家重点实验室开放基金项目(SKLFSE201107) 国家自然科学基金项目(41271080);国家自然科学基金创新群体项目(41121061)资助国家重点基础研究发展计划(973计划)项目(2012CB026102) 中国科学院西部行动计划项目(KZCX2-XB3-19)
【分类号】：U416.1

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