摘要
在野外水文地质调查的基础上，采集大沽河下游咸水入侵区砂样，通过室内渗流柱咸淡水驱替试验，分别研究了盐度突变和渐变条件下咸淡水界面上含水介质的水敏感性。研究结果表明，在盐度突变条件下含水多孔介质的渗透系数下降了50．0％，而在盐度渐变条件下渗透系数只下降了25．1％，溶液盐浓度递减速率越快则渗透性降低程度越大；随着渗透时间的延长，渗透系数可降低1～3个数量级，且渗透性的降低具有不可逆性。另外，本区渗透性发生变化主要是由伊利石、高岭石和绿泥石这些非膨胀性粘粒在渗流柱内迁移和沉积引起的。
Based on the geohydrological investigation in the fields, seawater and freshwater were made to flow through two columns filled with the samples from the downstream of the Dagu River. The water sensitivity at saline -freshwater interface was discussed by changing salinity sharply and gradually. The results showed that the permeability of the porous media was decreased by 50.0% when the seawater was flushed by freshwater. However, the decrease of permeability is comparatively slow and the permeability was decreased by 25.1% in the case of gradual salinity decrease. The faster rate of salinity decrease, the water sensitivity damage is more serious. A significant decrease of hydraulic conductivity with the order of 10.2 to 10.5 was observed with time and the decrease is irreversible. The migration and interception of the released clay particles such as illite, kaolinite and chlorite were changed due to salinity changes.
出处
《海洋环境科学》
CAS
CSCD
北大核心
2007年第4期301-304,312,共5页
Marine Environmental Science
基金
国家自然科学基金项目(40572142)
关键词
咸淡水界面
粘粒
多孔介质
水敏感性
saline-freshwater interface
clay particle
porous media
water sensitivity
