| 温度-湿度-荷载综合作用下路基冻融过程试验研究 |
| |
| 引用本文： | 毛雪松,杨锦凤,张正波,郑小忠,周雷刚.温度-湿度-荷载综合作用下路基冻融过程试验研究[J].冰川冻土,2012,34(2):427-434. |
| |
| 作者姓名： | 毛雪松 杨锦凤 张正波 郑小忠 周雷刚 |
| |
| 作者单位： | 长安大学特殊地区公路工程教育部重点实验室,陕西西安,710064;西藏自治区交通科学研究所,西藏拉萨,850001 |
| |
| 基金项目： | 国家自然科学基金项目，交通部科技项目，2011年西藏自治区科技计划项目资助 |
| |
| 摘 要： | 为了研究季节冻土路基内部温度场、水分场及应力场综合效应的变化特性,基于自主研发的温度-湿度-荷载综合模型试验测试系统,进行室内路基模型的冻结与融化循环试验,分析了冻融循环过程路基内部土体水、热及力学性能的变化特性.试验表明:冻结过程中,初期温度变化大,温度梯度从顶端向底部逐渐递减;路基顶冻结后,0℃冻结锋面不断往下移动,0℃分界线两段内温度梯度差异大;路基含水率分为冻结区未冻水含量似稳定段、过渡区未冻水快速相变段、未冻结区含水率减小段.融化过程中,温度变化先大后小,未冻结水含量与温度大小相关,路基内部含水量呈现中间增大,两端减小的情形.水热综合作用下,应力场表现:冻融过程中,路基回弹模量随着冻结深度的增大呈线性增加,随融化深度的增加而减小;路基回弹模量随冻融循环次数增加而衰减,当达到6次时,衰减趋于稳定.结果表明,土体水热耦合作用是影响路基土体力学性能的关键因素.
|
| 关 键 词： | 温度场 湿度场 应力场 综合效应 冻融循环 |
Experimental Study of Integrated Temperature-Moisture-Load Effect on Subgrade during Freeze-Thaw Cycle |
| |
| MAO Xue-song,YANG Jin-feng,ZHANG Zheng-bo,ZHENG Xiao-zhong,ZHOU Lei-gang.Experimental Study of Integrated Temperature-Moisture-Load Effect on Subgrade during Freeze-Thaw Cycle[J].Journal of Glaciology and Geocryology,2012,34(2):427-434. |
| |
| Authors: | MAO Xue-song YANG Jin-feng ZHANG Zheng-bo ZHENG Xiao-zhong ZHOU Lei-gang |
| |
| Institution: | 1(Key Laboratory of Special Area Highway Engineering of Ministry of Education,Chang’an University,Xi′an Shaanxi 710064,China; Transportation Science Institute of Tibet,Lhasa Tibet,850001 China) |
| |
| Abstract: | In this paper,in order to study the variation characteristics of integrated effect of temperature field,moisture field and stress field on seasonally frozen soil inside subgrade,variation characteristics of hydrothermal and mechanical properties of soil inside subgrade during freeze-thaw cycle are analyzed from an experiment of freeze and thaw cycle on subgrade model in indoor,based on an independently developed test system for compositely modeling temperature-moisture-load.The results indicate that temperature variation is more at the beginning,with temperature gradient gradually decreasing from top to bottom;0 ℃ freezing front moves down continuously,and after subgrade top frozen,temperature gradient has great difference between the two segments upon and below the 0 ℃ separatrix;during the freezing process,water content in subgrade can be divided into frozen area with homo-stable unfrozen water,transition area with unfrozen water of fast phase change and unfrozen area with reducing moisture.During the thawing process,specimen has great temperature variation at first,and then becomes less and less;unfrozen water content is depend on temperature;water content is more in the middle and less in both ends.Under the composite effect of hydrothermal,the stress field is characterized by a resilient modulus of subgrade linearly increasing with frozen depth,but decreasing with thawed depth;resilient modulus of subgrade decreases with freeze-thaw cycles.When the cycles reach to 6,attenuation tends to be stable.The results show that coupling action of temperature and water is the key factor that controls the mechanical properties of soil in subgrade. |
| |
| Keywords: | temperature field moisture field stress field composite effect freeze-thaw cycles |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
|
