高海拔冻土区通风管路基管内风速及影响因素研究  

Characteristics and influence factors of wind speed in ventilation duct of ventilation duct embankment in high altitude permafrost regions

作　　者：宋正民 穆彦虎 马巍 俞祁浩 栗晓林 SONG Zhengmin;MU Yanhu;MA Wei;YU Qihao;LI Xiaolin(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2021年第4期1111-1120,共10页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41772325,41630636);甘肃省交通运输厅科研项目(No.2017-008)资助。

摘　　要：在多年冻土地区,路基工程的修筑将对下伏多年冻土的热力稳定性产生显著的影响。为保护多年冻土,保证路基的长期稳定性,通风管作为一种对流换热类主动冷却降温措施被广泛应用。通风管内的对流换热强度与管内风速密切相关,针对这一问题,采用现场监测与数值模拟相结合的方式开展了通风管内风速特征及影响因素的研究。结果表明:随通风管管径的增加,管内风速呈抛物线型增加,当管径达到0.6 m后,管内风速增加不再明显;通风管外伸长度对管内风速的影响较小,但随环境风速的增加这一影响逐渐加强;管内风速随通风管的埋设高度的增加呈线性增加,当通风管的埋设高度达到2 m后,管内风速受路基高度的影响较小;此外,在两幅路基并行条件下,受上风向路基的遮挡作用,下风向路基管内风速明显降低,以两幅路基管内风速差值不超过0.4 m·s^(-1)为标准,路基高度为3 m时两幅路基最小间距为50 m。In high altitude permafrost regions,roadway embankment construction will exert significant impacts on underlying permafrost thermal regime.In order to protect the long-term stability of permafrost subgrad,venti⁃lation duct embankment is an effective cooling measure used in roadway construction.For ventilation duct em⁃bankment,wind speed in ventilation duct is an important factor determining the intensity of convection heat transfer between environment and embankment filling.In this paper,characteristics and influence factors of wind speed in ventilation duct of ventilation duct embankment are studied by field measurement and numerical simulation.The results shows that wind speed in ventilation duct increase exponentially with increasing diameter of the duct.But when the diameter of the duct is greater than 0.6 m,the wind speed does not increase further.The influence of extended length of the ventilation duct on the wind speed is slight,but with increasing environ⁃mental wind speed the influence becomes considerable.The wind speed in the ventilation duct add with increase in ventilation duct buried depth.When the buried depth is greater than 2 m,the wind speed does not change con⁃siderable.When roadway is constructed with two separated embankments,the wind speed in ventilation duct of the leeward embankment will be influenced by the windward embankment.Taking the discrepancy of wind speeds in the ventilation ducts of the two embankments not exceeding 0.4 m·s^(-1 )as a standard,the minimum spacing between the two separated embankments is about 50 m with their thickness being 3 m.

关 键 词：多年冻土区 通风管路基 风速 路基高度 

分 类 号：P642.2[天文地球—工程地质学]