不同上限粒径泥石流浆体的流变参数变化规律  

Rheological parameters of debris flow slurries with different maximum grain sizes

作　　者：杨红娟[1,2] 韦方强[2] 胡凯衡[2] 吕娟[2] 

机构地区：[1]中国科学院山地灾害与地表过程重点试验室,四川成都610041 [2]中国科学院水利部成都山地灾害与环境研究所,四川成都610041

出　　处：《水利学报》2016年第7期884-890,共7页Journal of Hydraulic Engineering

基　　金：中国科学院重点部署项目(KZZD-EW-05-01);国家自然科学基金项目(41201011);中科院山地所"青年百人团队"项目(SDSQB-2013-01)

摘　　要：根据云南东川蒋家沟黏性泥石流原样颗分资料,利用泥石流堆积物配置4个黏性泥石流原样对应的上限粒径分别为0.25、1、2、5和10 mm的浆体,通过球系统开展流变试验,利用Herschel-Bulkley模型拟合流变曲线,研究较粗的颗粒加入细颗粒浆体后流变参数的变化规律。结果表明各样品均表现为剪切稀化流体,粗颗粒加入细颗粒浆体后浆体屈服应力增加,剪切稀化程度减弱;同样颗粒级配下,浆体的屈服应力随固体体积浓度指数增加。由于流动性指数的变化,粗颗粒加入后浆体稠度指数的变化没有明显规律,但是表观黏度增加,增幅略小于屈服应力的增幅。粗颗粒浆体与细颗粒浆体的相对黏度和相对屈服应力之间存在显著的线性关系,可根据该关系式对泥石流原样的表观黏度进行估算。According to the grain size distribution of viscous debris flows in Jiangjia Gully of Yunnan Prov-ince of China, four groups of debris flow slurries with different maximum grain sizes（0.25, 1, 2, 5 and10mm） were prepared. Each group corresponds to a specific density of debris flow. Rheological tests wereperformed with ball measuring system, and rheological parameters were then determined using the Her-schel-Bulkley model to study how these parameters vary as coarser grains were added to a finer-grainedslurry. The results show that all slurry samples behave as shear-thinning fluids, whereas they become lessshear-thinning and exhibit higher yield stress when coarser grains were added. For slurries with the samemaximum grain size,yield stress increases exponentially with volumetric solid concentration. There is no dis-tinct relationship between the consistency index and the maximum grain size because of the variation in flu-idity index. However, the apparent viscosity increases when coarser grains were added, and the increasingamplitude is a little less than that of the yield stress. A good linear relationship exists between the relativeviscosity and the relative yield stress of coarser-grained slurries to fine-grained slurries, which can beused to estimate the apparent viscosity of debris flow.

关 键 词：泥石流 浆体 流变参数 Herschel-Bulkley模型 蒋家沟 球系统 

分 类 号：P642.23[天文地球—工程地质学]