磷尾矿的电阻率与其力学性质关系的试验研究

发布时间：2018-10-21 16:37

【摘要】：电阻率是用来表示各种物质导电性的物理量。岩土的电阻率是工程物探方面的一个重要的物性参数。尾矿是矿山选矿甄别后的矿渣,属于人造土。它与天然土体因成因不同,在颗粒级配、尺寸大小、形状、物理化学性质等均有所不同。本文以磷尾矿为研究对象,通过室内试验,探讨了磷尾矿电阻率及其主要影响因素以及磷尾矿电阻率与其工程力学性质之间的关系。主要研究内容和取得了的创新性成果有:(1)总结了国内外关于土的电阻率的研究现状,了解了土电阻率的测试方法和影响因素、土电阻率的结构模型以及土电阻率与其工程力学性质之间的关系。在此基础上,探讨电阻率法运用到尾矿土的研究当中的可行性。(2)以磷尾矿为研究对象,分析了尾矿土电阻率室内测试的方法原理。(3)通过室内试验,研究了磷尾矿电阻率的主要影响因素,得出了磷尾矿的电阻率基本特性。试验结果表明,磷尾矿的电阻率随着含水率、温度、干密度、饱和度的增加呈现递减的趋势,随孔隙比、中值粒径的增加呈现递增的趋势。(4)在利用改装的三轴剪切仪对磷尾矿试件进行三轴剪切试验的同时,同步测量了电阻率的变化,获得了磷尾矿的内聚力和内摩擦角与初始电阻率的关系,以及磷尾矿应力-应变-电阻率关系曲线。试验结果表明,磷尾矿的电阻率随着含水率、温度、干密度的增加而减小;磷尾矿的初始电阻率与剪切强度、内聚力和内摩擦角呈现负相关性;在三轴剪切压缩过程中,磷尾矿的电阻率随着应变的增加呈先增加后减小的趋势。(5)利用固结仪对磷尾矿试件进行固结试验的同时,测量电阻率的变化,获得磷尾矿电阻率与其力学参数的变化规律。(6)在非饱和土电阻率结构模型的基础上,结合磷尾矿的物理特性,建立了磷尾矿的电阻率模型。
[Abstract]:Resistivity is a physical quantity used to express the electrical conductivity of various substances. The resistivity of rock and soil is an important physical parameter in engineering geophysical exploration. Tailings, which belong to artificial soil, are the slag of mine dressing and screening. It is different from natural soil in particle gradation, size, shape, physicochemical properties and so on. In this paper, the resistivity of phosphorus tailings and its main influencing factors, and the relationship between the resistivity of phosphorus tailings and their engineering mechanical properties are discussed through laboratory tests. The main research contents and innovative achievements are as follows: (1) the research status of soil resistivity at home and abroad is summarized, and the measuring methods and influencing factors of soil resistivity are understood. The structural model of soil resistivity and the relationship between soil resistivity and its engineering mechanical properties. On this basis, the feasibility of applying the resistivity method to the study of tailings is discussed. (2) taking the phosphorus tailings as the research object, the principle of the laboratory measurement method for the resistivity of the tailings is analyzed. (3) the laboratory tests are carried out. The main factors affecting the resistivity of phosphorus tailings are studied, and the basic characteristics of the resistivity of phosphorus tailings are obtained. The results show that the resistivity of phosphorus tailings decreases with the increase of water content, temperature, dry density and saturation. The increase of median particle size shows an increasing trend. (4) the change of resistivity is measured synchronously while the triaxial shear test of phosphorus tailings is carried out by using a modified triaxial shear meter. The relationship between the cohesion and friction angle of phosphorus tailings and the initial resistivity, and the stress-strain-resistivity curve of phosphorus tailings are obtained. The results show that the resistivity of phosphorus tailings decreases with the increase of water content, temperature and dry density, the initial resistivity of phosphorus tailings is negatively correlated with shear strength, cohesion and friction angle, and in the process of triaxial shear compression, the initial resistivity of phosphorus tailings is negatively correlated with shear strength, cohesion and friction angle. The resistivity of phosphorus tailings increases first and then decreases with the increase of strain. (5) the change of resistivity is measured while the consolidation test of phosphorus tailings is carried out by means of consolidation instrument. The change of resistivity and mechanical parameters of phosphorus tailings is obtained. (6) based on the structural model of resistivity of unsaturated soil and the physical characteristics of phosphorus tailings, the resistivity model of phosphorus tailings is established.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD926.4

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