换填垫层对多年冻土地基水热分布状态的影响
Effect of replacement cushion on water-heat distribution in permafrost foundation
摘要
Abstract
Road problems in the frozen soil areas of the Qinghai—Tibet Plateau have become increasingly severe due to climate and environmental changes and engineering thermal effects,including frequent hazard occurrences,poor prevention and maintenance measures,etc.Replacement cushion is widely used in the design and construction of frozen road engineering,playing an essential role in enhancing deformation resistance,frost damage and stability.However,the effects of replacement cushions on the water-heat distribution during the service period have not been taken seriously.Based on the permafrost foundation replacement of the Gongyu—Yu Expressway,a numerical test on the water-heat distribution of the foundation was carried out with three types of filling materials,i.e.fine sand,coarse sand and gravel in the paper.The influence mechanism of filling materials on the distribution and evolution of water-heat was studied by using silty clay without replacement as a reference.The results show that replacing the gravel has better temperature control performance and can effectively reduce the maximum melting depth.Replacement cushions change the spatial and temporal distribution of foundation moisture.The unfrozen water content in the replacement layer decreases significantly,and the unfrozen water flows from both sides of the foundation to the centre along the filling-soil interface.The replacement cushion causes the surface ponding to invade into deeper soil.Especially without active drainage measures,the magnitude and oscillation amplitude of the water content in the deep foundation increase significantly.The water permeability and thermal conductivity of filling materials are important factors affecting water-heat distribution and evolution in road foundations.The moisture migration caused by replacement is not conducive to the long-term maintenance of the mechanical properties of the foundation.Therefore,replacement should be carefully adopted in engineering practice and on the premise of fully considering the climate environment and topographic features of the road area.关键词
道路换填/冻土地基/模拟实验/水热分布/水分迁移Key words
road replacement/frozen foundation/simulation experiment/hydrothermal distribution/moisture migration分类
土木建筑引用本文复制引用
张军辉,曾宪璋,高峰,郑健龙,盛岱超..换填垫层对多年冻土地基水热分布状态的影响[J].中南大学学报（自然科学版）,2025,56(2):674-687,14.基金项目
国家自然科学基金资助项目(52025085,52338009,52308438) （52025085,52338009,52308438）
国家重点研发计划项目(2021YFB2600900) （2021YFB2600900）
国家博士后创新人才支持计划项目(BX20220259) （BX20220259）
湖南省自然科学基金资助项目(2023JJ40035) （2023JJ40035）
中国博士后面上基金资助项目(2023M730368) （2023M730368）
长沙市自然科学基金青年基金资助项目(kq2208234) （kq2208234）
公路养护技术国家工程研究中心开放重点基金资助项目(kfj220801)(Projects(52025085,52338009,52308438)supported by the National Natural Science Foundation of China （kfj220801）
Project(2021YFB2600900)supported by the National Key R&D Program of China （2021YFB2600900）
Project(BX20220259)supported by the National Postdoctoral Innovation Talent Support Program of China （BX20220259）
Project(2023JJ40035)supported by the Natural Science Foundation of Hunan Province （2023JJ40035）
Project(2023M730368)supported by the Postdoctoral Science Foundation of China （2023M730368）
Project(kq2208234)supported by the Natural Science Foundation for Young Scientist of Changsha （kq2208234）
Project(kfj220801)supported by the Open Key Fund of the National Engineering Research Centre of Road Maintenance Technologies) （kfj220801）
