非饱和重塑黄土SWCC试验与拟合研究  

Experiment and SWCC fitting study of unsaturated and remolded loess

作　　者：白雪亮 张彬[2] 王汉勋[2] BAI Xueliang;ZHANG Bin;WANG Hanxun(Northwest Engineering Corporation Limited,POWER CHINA,Xi’an 710065,Shaanxi,China;School of Engineering&Technology,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,陕西西安710065 [2]中国地质大学(北京)工程技术学院,北京100083

出　　处：《矿产与地质》2020年第5期988-994,共7页Mineral Resources and Geology

摘　　要：利用GCTS土-水特征曲线仪研究了颗粒级配对非饱和重塑黄土土-水特性的影响;通过Brooks&Corey、Van Genuchten、Gardner、Fredlund&Xing(3参数模型)、Fredlund&Xing(4参数模型)五种常用模型对试验数据进行了拟合分析,得到适合非饱和重塑黄土的SWCC(soil-water characteristic curve)数学模型;通过提出“滞回比”这一参数,初步研究了颗粒级配对土-水特征曲线滞回特性的影响;利用Gardner经验模型、Van Genuchten统计传导模型对非饱和重塑黄土试样的渗透系数进行了拟合分析。结果表明:Gardner和Van Genuchten模型对非饱和重塑黄土土-水特征曲线拟合效果最好,a值随颗粒粒径的增大而减小,n值随颗粒粒径的增大而增大,滞回比随着颗粒粒径的增大逐渐减小;非饱和重塑黄土试样渗透系数随基质吸力的变化而变化,同一种模型对渗透系数的预测在增减湿过程中渗透系数数值存在差别。By the GCTS soil-water characteristic curve instrument,the soil-water characteristic curves of different particle gradation samples are plotted to stduy and analyze the effect of distribution of grain size on unsaturated loess soil-water characteristics.The suitable soil-water characteristic curve equation for unsaturated and remolded loess can be obtained with the experimental data fitted by five kinds of commonly used SWCC(soil-water characteristic curve)model(Brooks&Corey,Van Genuchten,Gardner,Fredlund&Xing(3 parameters model),Fredlund&Xing(3 parameters model)).The parameter of"hysteretic ratio"is proposed to study the influence of particle gradation on the hysteretic characteristics of the soil-water characteristic curve preliminary.Gardner model and Van Genuchten model are used to study the permeability curve characteristics of unsaturated loess.The result shows that the models of Gardner and Van Genuchten have the best fitting effect on soil water characteristic curve of unsaturated and remolded loess.The a value decreases with the increase of grain size,the n value increases with the increase of grain size,and the hysteretic ratio decreases with the increase of grain size.The permeability coefficient of unsaturated and remolded loess samples varies with the change of matrix suction force.There is a difference of the permeability coefficient predicted by the same model in the humidification and dehumidification process.

关 键 词：非饱和黄土 SWCC数学模型 土-水特征曲线 拟合分析 

分 类 号：TU411[建筑科学—岩土工程]