摘要
为探究江西地区典型红黏土层人工冻结条件下冻胀融沉变形、温度场和水分场变化规律,该文采用封闭系统单向冻融试验,对不同冻结冷端温度条件下重塑红黏土试样开展研究,获得冻胀率、融沉系数、冻结温度场和水分场变化规律。试验结果表明,(1)试样在单向冻融过程中,冻胀、融沉位移变化可分为7个阶段;冻胀率、融沉系数随冻结冷端温度的降低逐渐减小,且融沉系数大于冻胀率;冻结冷端温度越低,冻结完成时间越短,且冻结完成时间与冷端温度呈指数相关。(2)土样冻结过程中,试样冷端温度越低,冻结锋面高度越高,冻结锋面高度与冻结时间呈指数关系。(3)试样在封闭系统单向冻融后水分场发生重分布,试样近冷端位置土体含水率略有增大,靠暖端位置含水率减小,冻结冷端温度越高,水分迁移量越大,冷端温度为-5℃时比为-15℃时含水率增加了4.97%。
In order to investigate the freezing and thawing deformation, temperature field and moisture field changes under the artificial freezing conditions of typical red clay layer in Jiangxi area, this paper adopts the closed system one-way freezing and thawing test to study the remodeled red clay specimens under different freezing cold end temperature conditions, and obtain the freezing and thawing rate, thawing coefficient, freezing temperature field and moisture field changes. The test results show that:(1) the freezing and thawing displacement changes of the specimens can be divided into 7 stages during the unidirectional freezing and thawing process;the freezing and thawing coefficients decrease gradually with the decrease of the freezing cold end temperature, and the thawing coefficient is larger than the freezing rate;the lower the freezing cold end temperature, the shorter the freezing completion time, and the freezing completion time is exponentially related to the cold end temperature.(2) In the process of freezing soil samples, the lower the cold end temperature of the specimen, the higher the height of the freezing front, and the height of the freezing front is exponentially related to the freezing time.(3) The moisture field redistribution occurs in the specimen after one-way freezing and thawing in the closed system, the moisture content of the soil near the cold end of the specimen slightly increases, and the moisture content decreases by the warm end, the higher the temperature of the cold end of freezing, the greater the moisture migration, and the difference of moisture content change increases by 4.97% when the cold end temperature-5 ℃ compared with-15 ℃.
作者
王升福
吕亮
刘光炎
罗成文
薛凯喜
李栋伟
WANG Shengfu;LYU Liang;LIU Guangyan;LUO Chengwen;XUE Kaixi;LI Dongwei(School of Civil&Architecture Engineering,East China University of Technology,Nanchang 330013,China)
出处
《森林工程》
北大核心
2022年第5期144-150,共7页
Forest Engineering
基金
国家自然科学基金项目(41977236
42061011
42167024)
江西省自然科学基金项目(20202BABL214044)
江西省教育厅科技计划项目(GJJ200701)
东华理工大学研究生创新项目(DHYC-202132)。
关键词
人工冻结
红黏土
冻胀融沉
温度场
水分重分布
Artificial freezing
red clay
frost heave and thaw settlement
temperature field
moisture redistribution
