摘要
黄土强度受含水状态的影响作用较为显著,其随含水状态的周期性变化而变化,进而引起一系列病害。为研究非饱和黄土中水蒸气和温度的扩散运移规律,通过室内填筑模型试验,在重塑黄土中通入高温高压水蒸气,分析了非饱和重塑黄土中水蒸气和温度扩散运移规律。试验结果表明:在非饱和重塑黄土中,水蒸气扩散范围近似为椭球形;水蒸气扩散速率沿径向逐渐减小,增加蒸气压,蒸气扩散速率、扩散范围和增湿程度都将增大;蒸气压在加速水分扩散的同时,加速了温度的运移,气压为50 kPa土体升温速率约为0.75℃·min-1,气压为200 kPa时升温速率1.12℃·min-1;土体密度越大,水蒸气扩散时受到土颗粒的阻碍越大,随着水蒸气径向扩散距离增大,这种阻碍作用越显著,含水率减小的量值越大。
The moisture content of loess have a significant influence on the strength of the soil.It changes with the cyclic change of moisture content,which leads to a series of diseases.In order to study the diffusion and migration law of water vapor and temperature in unsaturated loess,we analyze the water vapor and temperature diffusion migration in unsaturated remolded loess through the indoor filling model test.We inject the high temperature and high pressure water vapor into the remolded loess.The experimental results show that in unsaturated remolded loess,the range of water vapor diffusion is approximately ellipsoid.The water vapor diffusion rate decreases gradually along the radial direction.The vapor diffusion rate,diffusion range and humidification degree can increase with the vapor pressure increase.Vapor pressure accelerates water diffusion and also the temperature migration.The heating rate of soil is about 0.75℃·min-1 when the pressure is 50kPa and 1.12℃·min-1 when the pressure is 200kPa.The greater the soil particle hinders the water vapor diffusion when the density of the soil is more larger.The hindrance is more obvious and the larger the water content decreases with the increase of the radial diffusion distance of the water vapor.
作者
何陇霞
王旭
张延杰
李建东
尉晨煜
HE Longxia;WANG Xu;ZHANG Yanjie;LI Jiandong;YU Chenyu(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070;National and Provincial Joint Engineering Laboratory of Road&Bridge Disaster Prevention and Control,Lanzhou 730070)
出处
《工程地质学报》
CSCD
北大核心
2018年第5期1265-1271,共7页
Journal of Engineering Geology
基金
国家自然科学基金项目(41662017
41562014)资助
关键词
非饱和重塑黄土
水蒸气扩散
温度运移
含水率
Unsaturated remolded loess
Steam diffusion
Temperature migration
Moisture content
