摘要
以生活源污染质降解终端产物Na_(2)CO_(3)和Na_(3)PO_(4)的混合溶液为污染质溶液对中国徐州地区粉质黏土进行渗流,完成了10次干湿循环试验,分析了在生活源污染质干湿循环下粉质黏土性质的演化特征,并揭示了其演化机理。研究结果表明:粉质黏土在经过生活源污染质10次干湿循环的过程中,土体渗透性增强1~2个数量级,电阻率降低20~25Ω·m,密度先减小到2 g·cm^(-3)以下后有所回升,抗剪强度降低30 kPa左右,且渗流路径长的土体性质变化具有一定的滞后性;在干湿循环过程中土体表面干缩裂缝逐渐发育扩展;干湿循环土样渗流路径越短,元素的密度变化量越大;生活源污染质干湿循环下土体性质发生变化的主要原因是渗流冲刷作用、化学反应、Na^(+)离子吸附作用、湿胀干缩作用和重力下渗作用共同作用的结果。
This paper uses the mixed solution of Na_(2)CO_(3)and Na_(3)PO_(4)to percolate the silty clay in Xuzhou of China.It completes 10 times dry-wet cycles.The solution is a terminal product of degradation of municipal waste.The evolution characteristics of the properties of silty clay under the dry-wet cycles are analyzed,and the evolution mechanism is revealed.The results show that the permeability of silty clay increases,the resistivity decreases,the density first decreases and then rises,the cohesion and the angle of internal friction decrease,and the change of soil properties with a long seepage path has a certain lag,the dry shrinkage cracks on the surface of the soil develop and expand gradually,and the seepage path of the soil develops gradually during the dry and wet cycles.The shorter the seepage path of the soil samples,the greater the density variation of elements.The main reasons for the change of soil properties under the dry-wet cycles are the combination of seepage erosion,chemical reaction,Na^(+)ion adsorption,wet expansion,dry shrinkage,and gravity infiltration.
作者
郭玉良
曹丽文
蔡念
GUO Yuliang;CAO Liwen;CAI Nian(School of Resources and Earth Science,China University of Mining and Technology,Xuzhou 221116,China;Fujian College of Water Conservancy and Electric Power,Yongan 366000,China)
出处
《工程地质学报》
CSCD
北大核心
2022年第2期309-316,共8页
Journal of Engineering Geology
基金
国家自然科学基金(资助号:41972281,41372326,41072236)。
关键词
干湿循环
渗流
生活源污染质
性质演化
作用机理
Dry-wet cycle
Seepage
Pollution from living sources
Property evolution
Mechanism