不同氯离子浓度对硫酸盐渍土盐冻胀特性的影响研究  

Effects of Different Chloride Ion Concentrations on Salt-frost Heaving Characteristics of Sulfate Saline Soil

作　　者：周鑫磊 张卫兵[1,2] 任亚军 刘臻祥 李晓 雷过 ZHOU Xinlei;ZHANG Weibing;REN Yajun;LIU Zhenxiang;LI Xiao;LEI Guo(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Engineering Research Center Funded by Ministry of Education for Effective Utilization of Modern Agricultural Water Resources in Arid Areas,Yinchuan 750021,China)

机构地区：[1]宁夏大学土木与水利工程学院,宁夏银川750021 [2]旱区现代农业水资源高效利用教育部工程研究中心,宁夏银川750021

出　　处：《宁夏工程技术》2023年第2期158-163,共6页Ningxia Engineering Technology

基　　金：宁夏自然科学基金项目(2021AAC03067);宁夏高等学校一流学科建设项目(NXYLXK2021A03);宁夏大学研究生创新项目(GIP2021051)。

摘　　要：为探究不同氯离子浓度对硫酸盐渍土冻结温度和盐冻胀变形的影响,采用自制试验土柱,在硫酸钠质量分数为3%、含水率为最优含水率条件下,对7组不同的氯硫比(氯离子与两倍硫酸根离子摩尔质量的比值)工况进行降温试验,研究了冻结温度和盐冻胀变形随氯离子浓度增加的变化趋势。结果表明:氯离子降低了硫酸盐渍土冻结温度,且随着氯离子浓度的增大,其降低幅度增大,同时土体达到冻结温度的时间延长;氯离子改变了盐冻胀变形的温度区间,氯硫比为0.1~0.7时,硫酸盐渍土盐冻胀变形的起始温度高于不含氯离子硫酸盐渍土的起始温度,且相应温度区间大于不含氯离子硫酸盐渍土的温度区间,氯硫比为0.8时,与不含氯离子硫酸盐渍土的温度区间接近;氯离子对硫酸盐渍土的盐冻胀变形有明显的抑制作用,且抑制作用随氯离子浓度增大而增强。To investigate the influence of different chloride ion concentrations on the freezing temperature and salt-frost heave deformation of sulfate saline soils,test soil columns were used.Under the condition of 3%sodium sulfate mass fraction and optimal moisture content,temperature reduction tests for 7 different sets of chloride to sulfur ratio(the ratio of chloride ions to twice the molar mass of sulfate ions)working conditions were conducted,and the variation of freezing temperature and salt-frost heave deformation with the increase of chloride ion concentration was obtained.The results show that chloride ion reduce the freezing temperature of sulfate saline soil.With the increase of chloride ion concentration,the reduction increases greatly and the time to reach the freezing temperature is extended.Chloride ion changes the temperature range of salt-frost heaving deformation.When the chloride to sulfur ratio is 0.1 to 0.7,the starting temperature of salt-frost heaving deformation is higher than that without chloride ion,and the corresponding temperature range is larger than that without chloride ion.When the ratio is 0.8,the temperature range is close to that without chloride ions.Chloride ions have a significant inhibitory effect on salt-frost heave deformation of sulfate saline soils,and the inhibitory effect increases with the increase of chloride ion concentration.

关 键 词：含氯硫酸盐渍土 氯硫比 冻结温度 盐冻胀变形 温度区间 

分 类 号：TU448[建筑科学—岩土工程]