基于粒度熵概念的贝壳砂颗粒破碎特性描述

发布时间：2018-04-24 03:02

本文选题：贝壳砂 + 颗粒破碎　；参考：《岩土工程学报》2014年06期

【摘要】：对取自福建莆田湄洲湾海域的贝壳砂进行了不同围压、不同相对密度下的三轴排水剪切试验,同时考虑了尺寸效应的影响。依据试样试验前后粒径分布资料,在统计熵概念基础上提出颗粒破碎粒度熵模型对其破碎率进行了度量,并与Hardin颗粒破碎模型进行了比较,结果表明:贝壳砂颗粒破碎率与围压、相对密度及试样尺寸均有关系,在相同试验条件下,贝壳砂颗粒破碎程度随着试样尺寸的增加而增大,随着围压的增加而增大;当相对密度较低时,颗粒破碎率呈增大趋势;相对密度增加到较高值时,颗粒破碎程度减弱;贝壳砂三轴压缩前后的级配曲线均可以通过粒度熵模型参数表征,其中相对基础熵参数(NB)较好地反映了颗粒破碎程度大小,破碎率愈高,NB值愈小,NB与Hardin破碎率存在显着的线性关系。贝壳砂颗粒破碎粒度熵参数能较好地描述其颗粒破碎行为,为岩土介质材料的颗粒破碎分析提供了一个新的量化指标。
[Abstract]:A triaxial drainage shear test of shell sand from Meizhou Bay, Putian, Fujian Province was carried out under different confining pressures and relative densities, and the effect of size effect was considered. Based on the data of particle size distribution before and after the test, a particle breaking particle size entropy model was proposed based on the concept of statistical entropy, and its breakage rate was measured and compared with the Hardin particle breaking model. The results show that the crushing rate of shell sand particles is related to confining pressure, relative density and sample size. Under the same test conditions, the crushing degree of shell sand particles increases with the increase of sample size and increases with the increase of confining pressure. When the relative density is low, the particle breakage rate tends to increase; when the relative density increases to a higher value, the particle fragmentation degree weakens; the gradation curve of shell sand before and after triaxial compression can be characterized by the parameters of particle size entropy model. The relative basic entropy parameter (NB) well reflects the degree of particle breakage. The higher the breaking rate the smaller the NB value and the linear relationship between NB and Hardin breakage rate. The particle size entropy parameter of shell sand can describe its particle breaking behavior well and provide a new quantitative index for the particle breaking analysis of rock and soil media materials.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室;天津市政工程设计研究院;
【基金】：国家自然科学基金项目(51109208)
【分类号】：TU411.2

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