铁道科学与工程学报2024，Vol.21Issue(6)：2331-2341,11.DOI:10.19713/j.cnki.43-1423/u.T20231379
不同温度路径与干湿状态下粉砂质泥岩冻融特征及劣化机制
Freeze-thaw characteristics and deterioration mechanism of silty mudstone under different temperature paths and dry-wet conditions
摘要
Abstract
To study the evolutionary patterns and deformation characteristics of silty mudstone under freeze-thaw conditions,laboratory freeze-thaw cycle tests were conducted on the dry and saturated silty mudstone with freezing temperatures of-5,-10,and-20℃,and thawing temperature of 30℃,respectively.The freeze-thaw characteristics and deterioration mechanisms were revealed by scanning electron microscopy.The results show that the evolution of the frost-heaving force of saturated rock can be divided into five stages:incubation,steep increase,equilibrium,melting fluctuation,and dissipation.The peak of frost-heaving force increases with decreasing freezing temperature.The incubation time of frost-heaving force decreases with decreasing freezing temperature,exhibiting a quadratic relationship.The dry or wet state significantly impacts the frost deformation of silty mudstone.The frost deformation in saturated rock can be categorized into seven stages:cooling and freeze-shrinkage,cooling and freeze-heave,low-temperature freeze-shrinkage,freeze-shrinkage platform,heating and thaw expansion,heating and thaw contraction and thaw platform.The dry rock only experiences four stages:cooling and freeze-shrinkage,freeze-shrinkage platform,heating and thaw expansion,and thaw platform.The strain characteristics of saturated rocks during freeze-thaw are substantially greater than those of dry rocks.Both the residual strain and the maximum strain exhibit exponential growth under various temperature conditions.The magnitude of residual strain increases by 341.05με,377.27με,and 545.53με at freezing temperatures of-5,-10,and-20℃,respectively,and the maximum strain increases by 355.85με,476.64με,and 536.36με,respectively.There is a certain correspondence between frost deformation and frost-heaving force.The frost deformation reaches the peak when the frost-heaving force is generated.The secondary peak of the frost-heaving force during thawing corresponds to the peak of the thawing deformation.The degradation process of freeze-thaw encompasses temperature damage,corrosion damage,and frost damage.These factors repeatedly interact with each other and result in significant freeze-thaw degradation of silty mudstone.The research findings can offer valuable insights for optimizing the safety and operational aspects of engineering projects in cold regions.关键词
岩石力学/冻融循环/冻胀力/冻融变形/劣化机制Key words
rock mechanics/freeze-thaw cycle/frost-heaving force/frost deformation/deterioration mechanism分类
建筑与水利引用本文复制引用
曾铃,刘赛,于晓伟,刘杰..不同温度路径与干湿状态下粉砂质泥岩冻融特征及劣化机制[J].铁道科学与工程学报,2024,21(6):2331-2341,11.基金项目
国家自然科学基金资助项目(52108397,52378440,52078067,52078066,51838001) （52108397,52378440,52078067,52078066,51838001）
湖南省自然科学基金资助项目(2022JJ40485) （2022JJ40485）
湖南省自然科学基金杰出青年基金资助项目(2023JJ10045) （2023JJ10045）
湖南省水利科技项目(XSKJ2022068-26) （XSKJ2022068-26）
交通运输行业重点科技项目(2022-MS1-032) （2022-MS1-032）
长沙市杰出创新青年培养计划(kq2305023) （kq2305023）
