多年冻土区热棒路基降温调控效能研究  

Research on Thermosyphon Subgrade Cooling Regulation Efficiency in Permafrost Regions

作　　者：刘金修 李泽 李钰 周德平 LIU Jin-xiu;LI Ze;LI Yu;ZHOU De-ping(Xinjiang Academy of Transportation Science,Urumqi 830000,China;CCCC First Highway Consultants Co.Ltd.,Xi'an 710075,China)

机构地区：[1]新疆交通科学研究院,乌鲁木齐市830000 [2]中交第一公路勘察设计研究院有限公司,西安市710075

出　　处：《公路》2021年第2期20-27,共8页Highway

基　　金：国家自然科学基金青年科学基金项目,项目编号51408480。

摘　　要：为了研究多年冻土区地温变化规律及评价L型和直式热棒的地温调控效果,以某一级公路采用的热棒群降温工程措施为研究对象,以现场实时监测数据为基础,评价了热棒有效影响半径、作用期限和影响深度等因素对多年冻土路基的降温冷却效果,通过热传导理论和非线性分析方法,建立了不同监测时段的地温预测模型。研究表明:在垂直于路基中心线的水平方向上,热棒作用下的路基地温变化呈"弯沉盆曲线"型,最小有效影响半径为2.0m。在近路中心侧最低地温在-0.5℃以下,L型热棒降温效果更佳;而在近路肩侧最低地温基本处于0℃以下,直式热棒冷却效能优势较大。多年冻土路基地温变化近似呈现正弦波形曲线分布,单位周期内地温振幅随深度增加不断衰减,且存在相位滞后效应和偏距差异,经历两个冻融循环冷却期后,两种热棒段的路基最低地温降幅分别达到51.5%、50%。浅层地温受大气温度和黑色沥青路面聚热效应的影响波动幅度较大,但随着路基埋深的不断增大,其周期性波动逐渐削弱并逼近年平均地温。多年冻土地温预测值与实测值相关系数均在0.97以上,预测效果良好。研究成果可为多年冻土路基设计、运营维护和变形监测提供新视野。In order to study the law of ground temperature variation and evaluate the temperatureadjusted effect of L-shaped and ordinary thermosyphon in permafrost regions,the thermosyphon cooling project adopted at a certain level of highway is taken as the study object.Based on real-time monitoring data in the field,the effect of factors such as the effective radius of thermosyphon,the duration of action and the influence depth on the cooling effect of the permafrost subgrade is evaluated.The ground temperature prediction model for different monitoring periods is established by means of the heat conduction theory and nonlinear analysis methods.The study shows that:in the horizontal direction perpendicular to the center of the subgrade,the variation of the subgrade temperature is"sinker basin"under the action of thermosyphon,and the minimum effective radius is 2.0 m.The lowest ground temperature near the center side is below-0.5°C,and the L-shaped thermosyphon has a better cooling effect;while the lowest ground temperature near the shoulder side is basically below 0°C,and the ordinary thermosyphon has better cooling efficiency.The permafrost subgrade temperature changes approximately as a sinusoidal curve,and the ground temperature amplitude decays continuously with depth in a unit period,and there are phase lag effects and offset distance differences.After two freeze-thaw cycle cooling periods,the lowest temperature decreasing amplitude of the thermosyphon subgrade reaches up to 51.5%and 50%respectively.The shallow ground temperature is affected by the atmospheric temperature and the thermal effect of the asphalt pavement.However,as the subgrade depth increases,the periodic fluctuations gradually weaken and approach the average ground temperature in recent years.The correlation coefficient between predicted value and measured value of permafrost temperature is above0.97,and the forecasting effect is good.The research results can provide a new perspective for the design,operation,maintenance and deformation monitoring o

关 键 词：道路工程 多年冻土 热棒路基 降温调控效能 地温预测模型 

分 类 号：U416.1[交通运输工程—道路与铁道工程]