岩土力学2018，Vol.39Issue(5)：1573-1580,8.DOI:10.16285/j.rsm.2017.0763
珊瑚砂高压力下一维蠕变分形破碎及颗粒形状分析
Fractal breakage and particle shape analysis for coral sand under high-pressure and one-dimensional creep conditions
摘要
Abstract
Coral sand is a type of marine biogenic granular material with extremely high calcium content.From the microscopic viewpoint,coral sand grains are characterized as highly angular,irregular in shapes and crushable.One-dimensional creep tests were conducted on coral sand under very high pressure to investigate the evolution of particle size distribution and change of particle shapes caused by particle breakage.Benefited from particle size analysis and shape evaluation with high speed dynamic image analysis apparatus,the evolution of particle shape along with stress was analyzed statistically,and shape factors including aspect ratio,sphericity and convexity increase with increasing pressure.Shape factors for particles with different sizes tend to reach a same value,which illustrated that the morphology of particle after breakage is scale independent and self-similar in this wide range of sizes.This paper analyzed the fractal feature after particle breakage,and found that the fractal dimension increases with increasing vertical stress,and eventually reaches the fractal ultimate breakage (D=2.5).This paper calculated the relative breakage by using Hardin's and Einav's methods,and found that relative breakage is increasing along with increasing pressure.The relative breakage is an exponent function with the pressure,which could be used to predict the relative breakage if the material and pressure are known.The increasing tendency with time is not obvious,because particle breakage is majorly caused by compression instead of creep.关键词
珊瑚砂/分形/颗粒形状/蠕变/颗粒破碎Key words
coral sand/fractal/particle shape/creep/particle breakage分类
建筑与水利引用本文复制引用
张小燕,蔡燕燕,王振波,江芸倩..珊瑚砂高压力下一维蠕变分形破碎及颗粒形状分析[J].岩土力学,2018,39(5):1573-1580,8.基金项目
国家自然科学基金项目(No.51774147) （No.51774147）
中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金(No.SKLGDUEK1701) （No.SKLGDUEK1701）
福建省自然科学基金项目(No.2017J01094) （No.2017J01094）
中央高校基本科研业务费(No.2017QL04). This work was supported by the National Natural Science Foundation of China (51774147),the Open Research Fund of State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology (SKLGDUEK1701),the Natural Science Foundation of Fujian Province of China (2017J01094) and the Fundamental Research Funds for the Central Universities (2017QL04). （No.2017QL04）
