干湿循环作用下不同围压尾砂的力学特性  

Mechanical Properties of Tailings under Different Confining Pressures and the Circulation of Moisture Absorption and Desorption

作　　者：郭要辉 田亚坤 伍玲玲[1,2] 张志军 窦玫琦[1] 贺桂成 喻清[1,2] GUO Yaohui;TIAN Yakun;WU Lingling;ZHANG Zhijun;DOU Meiqi;HE Guicheng;YU Qing(School of Resource&Environment and Safety Engineering,University of South China,Hengyang 421001,China;Hunan Provincial Mining Geotechnical Engineering Disaster Prediction and Control Engieening Technology Research Center,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学资源环境与安全工程学院,湖南衡阳421001 [2]南华大学湖南省矿山岩土工程灾害预测与控制工程技术研究中心,湖南衡阳421001

出　　处：《有色金属工程》2020年第4期87-93,共7页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(51774187,51804164,51974163);湖南省自然科学基金项目(2019JJ50498,2017JJ3274);湖南省教育厅科研基金(17A184,18B276);湖南省联合工程中心开放课题项目(2018ykzx2006)。

摘　　要：为探究吸湿脱湿循环作用下湖南省某尾矿库尾砂在不同围压下力学行为的变化规律,对尾砂试样进行0~6次吸湿脱湿循环试验。在围压为100、200、300 kPa的情况下分别对特定的尾砂试样进行室内常规三轴试验,得到了尾砂试样的承载能力变化趋势、吸湿脱湿循环对尾砂试样黏聚力和内摩擦角的影响、孔隙水压力与剪缩剪胀之间的关联等力学特性。试验结果表明:随着吸湿脱湿循环次数的增加,尾砂试样强度逐渐减弱且初次吸湿脱湿循环后强度下降较明显;吸湿脱湿循环导致尾砂试样内摩擦角和黏聚力下降;孔隙水压力的变化趋势在一定程度上能反映试样的剪缩剪胀特性;吸湿脱湿循环和高围压作用对试样的剪胀特性均有一定的抑制作用。In order to explore the variation of the mechanical properties of tailings with the circulation of moisture absorption and desorption under different confining pressures,using tailing samples taken from a tailings pond in Hunan Province in this study,triaxial undrained shear tests were performed at confining pressure of 100 kPa,200 kPa and 300 kPa on the tailing samples after 0-6 cycles of moisture absorption and desorption action.This paper analyzed the mechanical properties of the changing trend of loading capacity,the effect of moisture absorption and desorption cycle on the cohesion and internal friction angle of tailings,and the relationship between pore water pressure and shear shrinkage and dilatation.The test results showed that when the number of moisture absorption and desorption cycles increases,the strength of the tailings sand sample was weakened,and the strength decreased obviously after the first moisture absorption and desorption cycle.In addition,the circulation of moisture absorption and desorption results in the decrease of internal friction angle and cohesion of tailings.The variation trend of pore water pressure can reflect the shear dilatancy and shrinkage characteristics of the tailings sand sample to some extent.However,the moisture absorption and desorption action and the high confining pressure have a certain inhibiting effect on the dilatancy characteristics of the samples.

关 键 词：尾矿砂 吸湿脱湿 剪胀 孔隙水压力 

分 类 号：TD926.4[矿业工程—选矿]