摘要
为研究含水率、含盐量对伊犁盐渍化黄土水盐迁移机制的影响,开展了含盐黄土在冻融循环作用下的水盐迁移试验,分析了温度场、水分场和盐分场及其黏聚力变化规律。结果表明:在冻融作用下,盐渍化黄土的温度场、水分场和盐分场均表现出周期性变化;随着冻融循环次数的增加,土柱的含水率整体会提高,呈现出两端含水率高,中间含水率低的形态;冻融作用下土层的盐分变化与水分的总体变化具有一致性,未冻融前各土层盐分呈现均匀分布;在温度势的作用下,水分携带盐分向上迁移,导致土柱中上部分含盐量较高;含水率和含盐量的提高对水分和盐分迁移具有的促进作用;含水率的提高会在土颗粒之间起到润滑作用,导致低含水率的试样其黏聚力大于高含水率的试样;随着含盐量的提高,盐晶包裹土粒形成的团聚体起到骨架作用,使得高含盐量试样的黏聚力大于低含盐量的试样;冻融作用后盐渍化黄土的内摩擦角值呈现波浪分布。
In order to study the influence of different water content and salt content on the water-salt migration mechanism of Ili salinized loess.The water-salt migration test of saline loess under the action of the freeze-thaw cycle was carried out,and the temperature,moisture,and salt fields and their cohesion change rules were analyzed.The study shows that under the action of freezing and thawing,the temperature field,moisture field and salt field of saline loess show cyclic changes.With the increase of the number of freezing and thawing cycles,the water content of the soil column as a whole is increased,showing a pattern of high water content at the two ends and low water content in the middle.The change of salts in the soil layer under freezing and thawing is consistent with the overall change of moisture,and the salts in each soil layer show a homogeneous distribution before the unfreezing and thawing.Under the effect of temperature potential,the water carries the salts to migrate upward,resulting in higher salinity in the middle and upper part of the soil column.The increase of water content and salinity has a promoting effect on the migration of water and salts.In addition,the increase in water content will have a lubricating effect between the soil particles,resulting in the cohesion of the sample with low water content being greater than that of the sample with high water content.With the increase of salt content,the agglomerates formed by the salt crystals wrapped around the soil particles play the role of skeleton,which makes the cohesion of the specimen with high salt content larger than that of the specimen with low salt content,the value of internal friction angle of salinized loess after freeze-thawing shows a wave distribution.
作者
包卫星
吴倩
吴谦
秦川
侯天琪
Bao Weixing;Wu Qian;Wu Qian;Qin Chuan;Hou Tianqi(School of Highway,Chang'an University,Xi'an 710064,P.R.China)
出处
《地下空间与工程学报》
北大核心
2025年第6期1976-1987,共12页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(52308435)
新疆维吾尔自治区重大科技专项项目(2020A03003-7)
陕西省自然科学基础研究计划(2021JM-180)。
关键词
路基工程
盐渍化黄土
冻融循环
水盐迁移
黏聚力
内摩擦角
roadbed engineering
salinized loess
freeze-thaw cycles
water-salt migration
cohesion
internal friction angle
