冻融过程中重塑土水盐迁移的试验研究

发布时间：2018-02-16 21:12

本文关键词： 盐渍土冻融重塑土水盐迁移　出处：《科学技术与工程》2017年30期 　论文类型：期刊论文

【摘要】：为探究盐渍土地基冻融过程中的水盐迁移规律,以内蒙古东部典型盐渍土为研究对象,通过改变土样冷端温度,初始含水率,干密度和含盐量等因素,进行室内重塑土单向冻结、双向融化试验。结果表明:试样温度的改变存在滞后性;离冷端越近,温度变化越敏感;在冻结过程中,土样初始含水率、干密度或者含盐量的增大,将造成冻结锋面的移动速度减小。试件水分迁移量随着初始含水率的增大而增大;当初始含水率较低时,冷端温度的变化对水分迁移影响较小;只有当初始含水率足够大时,迁移量才随着冷端温度的降低而增大;土溶液冻结和电导率突变存在关联性;含盐量的增加,会抑制水分迁移。试件整体盐分迁移量随着冷端温度的降低而增大;只有当冷端温度足够低时,盐分迁移量才会随着初始含水率的增大而增大;增大干密度会减少盐分迁移;含盐量的增多,使盐分往试件暖端方向汇聚。
[Abstract]:In order to investigate the law of water and salt migration in the freezing and thawing process of saline soil foundation, the typical saline soil in the east of Inner Mongolia was studied by changing the cold end temperature, initial moisture content, dry density and salt content, etc. Laboratory remolded soil was subjected to unidirectional freezing and bidirectional melting test. The results show that the change of sample temperature is hysteresis, the closer the sample is to the cold end, the more sensitive is the temperature change; during the freezing process, the initial moisture content of the soil sample, The increase of dry density or salt content will result in the decrease of the moving velocity of the freezing front. The water migration of the specimen increases with the increase of the initial moisture content, and the change of the cold end temperature has little effect on the water migration when the initial moisture content is low. Only when the initial moisture content is large enough, the migration increases with the decrease of cold end temperature, the freezing of soil solution is related to the sudden change of conductivity, and the salt content increases. The whole salt migration increases with the decrease of cold end temperature; only when the cold end temperature is low enough, the salt migration increases with the increase of initial moisture content, and the increase of dry density decreases the salt migration. The increase of salt content makes the salt converge to the warm end of the specimen.
【作者单位】：东北林业大学土木工程学院;东北林业大学寒区科学与工程研究院;东北林业大学工程技术学院;
【基金】：国家自然科学基金(41641024)资助
【分类号】：TU448

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