成都粘土泥浆流变模型探讨  

Discussion on the Rheological Model of Chengdu Clay Slurry

作　　者：梁瑛[1] 曹文豪 季宪军[1] 潘华利[2] 欧国强[2] LIANG Ying;CAO Wenhao;JI Xianjun;PAN Huali;OU Guoqiang(Nanyang Institute of Technology, Nanyang 473004, He'nan, China;Institute of Mountain Hazards and Environment, Chinese Academy of Science, Chengdu 610041, China)

机构地区：[1]南阳理工学院,河南南阳473004 [2]中国科学院、水利部成都山地灾害与环境研究所,成都610041

出　　处：《山地学报》2021年第2期218-225,共8页Mountain Research

基　　金：国家自然科学基金(41672357,51679229,41672318)。

摘　　要：泥浆是泥石流动力学的重要研究对象。细小的黏性颗粒是黏性泥石流泥浆的基本组成部分,传统流变模型可以描述粘性泥石流中颗粒物质相互作用,然而各灾害点物质组成的差异性使得泥浆流变模型的应用各有不同,且当前研究缺少对不同模型应用的详细讨论。本研究利用MCR301流变仪,开展不同含水量成都粘土泥浆流变实验,分析成都粘土泥浆剪切应力随剪切速率变化过程、含水量对剪切应力的影响;对比分析幂律模型、宾汉模型和Herschel&Bulkley模型(H-B模型),拟合各含水量成都粘土泥浆的流变实验结果。得出如下结论:(1)随着含水量由50%增大到400%,成都粘土泥浆切应力迅速降低,由超过8000 Pa降低到5 Pa左右;当剪切速率约为0.2 s-1时,剪切应力随剪切速率增加而迅速增大,但当剪切速率大于0.2 s-1时,剪切应力随剪切速率增加而增长缓慢,成都粘土泥浆表现出典型的剪切稀化非牛顿体流体;(2)H-B模型能很好地反映各含水量成都粘土泥浆剪切应力与剪切速率的变化全过程(剪切稀化),是拟合成都粘土泥浆流变过程的最佳数学模型;(3)泥浆屈服应力(τHB)和流动指数(ηHB)随含水量的增加迅速减小。本文流变模型实验的开展和研究对深入认知和探索泥石流致灾全过程具有重要意义。To understand the mechanical properties of slurry in debris flow fluid is a prerequisite for recognizing the movement process of debris flow.A proper rheological model of slurry in debris flow body can contribute to a better understanding of the process of debris flow initiation and the process of the particles interaction during moving of the viscous debris flow.In this study,MCR301 rheometer was used in the laboratory testing of slurry properties,it conducted rheological experiments on the slurries of Chengdu Clay.The change process of shear stress with shear rate was analyzed,following by the influence of water content on shear stress.It introduced power law model,Bingham model and Herschel&Bulkley model separately to compare the fitting of the rheological test results of the Chengdu Clay slurry with various water contents.The following conclusions were drawn as hereafter:(1)The shear stress of the Chengdu Clay slurry decreased rapidly from more than 8000 Pa to about 5 Pa with the increase of water content from 50%to 400%.As the shear rate was small(about 0.2 s-1),the shear stress increased rapidly with the increase of shear rate.In the case of the shear rate exceeding a certain value,the shear stress increased slowly with the increase of shear rate,suggesting that the Chengdu Clay slurry be a typical shear-thinning non-Newtonian fluid definitely;(2)H-B model could well reflect the whole process of shear stress with shear rate(shear-thinning)of the clay slurry with varied water contents,and it was recognized as the best mathematical model for the fitting of rheological process of the slurry of Chengdu Clay;(3)On this basis,the influence of water content on the rheological parameters(τHB、ηHB)of Chengdu Clay mud was analyzed,and the conclusion that the yield stress(τHB)and flow index(ηHB)of Chengdu Clay mud decrease rapidly with the increase of water content was obtained.Based on the rheological experiment,this paper discusses the rheological model of mud,which is of great significance for further understa

关 键 词：成都粘土 泥浆 流变实验 流变模型 H-B模型 

分 类 号：P642.2[天文地球—工程地质学]