冻土地区铁路路基主动供热防冻胀方法现场试验研究  

Field Tests on Active Heating Method for Preventing Frost Heave in Railway Embankments in Cold Regions

作　　者：胡田飞 张宗凯 张晓东 何宝华 王力 HU Tianfei;ZHANG Zongkai;ZHANG Xiaodong;HE Baohua;WANG Li(State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Key Laboratory of Mechanical Behavior Evolution and Control of Traffic Engineering Structures in Hebei,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;National Energy Group Xinshuo Jungar Banner-Shenchi Railway(Shanxi)Co.,Ltd.,Shuozhou 036002,China)

机构地区：[1]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,河北石家庄050043 [2]石家庄铁道大学河北省交通工程结构力学行为演变与控制重点实验室,河北石家庄050043 [3]石家庄铁道大学土木工程学院,河北石家庄050043 [4]国能新朔准池铁路(山西)有限责任公司,山西朔州036002

出　　处：《铁道学报》2024年第4期156-166,共11页Journal of the China Railway Society

基　　金：国家自然科学基金(42001059);中央引导地方科技发展资金(226Z5402G);河北省自然科学基金(E2020210044,E2023210064);河北省创新能力提升计划(225676162GH,21567606H)。

摘　　要：路基冻胀是冻土地区铁路运营的顽疾,在防排水、土质改良和保温等措施难以消除冻胀的情况下,人工供热是一种备选方案。依托准池铁路K44+970—K45+020冻害路段,设计基于地源热泵的分布式供热方案,建设1个长度为20 m的现场试验段。在2021—2022年冬季开展1个冻融周期的供热试验,基于监测数据对热泵换热温度、路基温度场、冻结深度、轨道变形量等指标进行分析。研究结果表明:热泵的供热温度可达50℃以上,热源品位高且供热量稳定。供热试验段内路基冻结范围和温度极值比天然工况显著减小,线路中心处最大冻结深度由148 cm减小为88 cm,冻结锋面保持在地下水毛细迁移高度以上。试验段路基横向冻结深度差值由天然条件的49 cm减小为13 cm,有利于消除横向冻胀差异引起的水平不平顺。试验段纵向上的冻结深度差值基本控制在20 cm以内,可以避免次生高低不平顺。天然路基呈先发育深层冻胀、后在降雪融水入渗时发育浅层冻胀的规律,最大冻胀量达9.4 mm。试验段内路基未发育深层冻胀,且浅层冻胀量得到有效控制,轨道变形量控制在±3 mm以内,没有超出作业验收管理值,有效缓解了试验段冻害问题。Embankment frost heave is a persistent problem in railway operation in cold regions.Active heating is an alternative way,when traditional waterproof and drainage,soil improvement and thermal insulation measures fail.In this study,a distributed heating system based on ground source heat pump was designed for the K44+970—K45+020 frozen damage section of Jungar—Shenchi railway,and a 20 m long on-site heating section was constructed.A freeze-thaw cycle heating test was carried out in the winter of years 2021—2022,to analyze the heat exchange temperature of heat pump,temperature field of natural and heating embankment,freezing depth and track deformation based on the monitoring data.The results show that the heating temperature of the heat pumps can reach above 50℃,with high heat source grade and stable heating capacity.Both the frozen range and extreme temperature value of the embankment in the heating test section are significantly reduced compared to natural conditions.The maximum freezing depth at the horizontal center of the line is reduced from 148 cm to 88 cm,with the freezing front maintaining above the capillary migration range of groundwater.The freezing depth difference in horizontal direction is reduced from 49 cm in natural conditions to 13 cm,which is conducive to eliminating the horizontal track irregularity caused by lateral frost heave differences.The longitudinal freezing depth difference controlled within 20 cm can avoid secondary vertical track irregularity.The natural embankment near the test section shows the law of developing deep frost heave first,followed by shallow frost heave during snowmelt infiltration,with a maximum frost heave deformation of 9.4 mm.However,in the test section,deep frost heave has not developed and shallow frost heave is effectively controlled.The deformation of the track,controlled within±3 mm,is within the maintenance management value.The active heating method has effectively alleviated the problem of embankment frost heave in the test section.

关 键 词：路基冻胀 分布式供热系统 地源热泵 供热温度 温度场 冻结深度 冻胀量 

分 类 号：TU431[建筑科学—岩土工程] U213.7[建筑科学—土工工程]