摘要
级配结构是影响破碎矸石压实和再破碎特征的重要因素,而级配矸石的压实和再破碎特征直接决定了采空区充填质量和效果。首先,采用分级加载方式对连续级配和间断级配的破碎矸石进行侧限单轴压缩试验;基于试验结果,研究轴向应力和级配共同影响下的压实变形参数、再破碎参数的变化规律,分析再破碎后颗粒的粒径分布和分形特征。然后,以级配压实-破碎—分形演化为研究路线,建立分别表征压实和分形特征的压实度增量与分形维数之间的关系式,以及分别表征压实和再破碎特征的应变与分形维数增量之间的关系式,并论证关系式中参数的物理意义,探讨级配矸石压实和再破碎过程之间的内在关系。研究结果表明:根据压缩模量变化规律及其不同阶段的压实变形机理,可将不同级配破碎矸石压实阶段划分为快速压实、缓慢压实和稳定压实3个阶段,颗粒再破碎后的粒径分布特征表明颗粒的再破碎主要发生在缓慢压实阶段;本文提出的关系式较好地描述了级配破碎矸石的压实—再破碎全过程,可反映不同级配矸石在压实和再破碎过程中的稳定性,可为采空区精准充填及其预防提供理论依据。
The grading structure is an important factor affecting the compaction and re-crushing characteristics of crushed gangue, and the compaction and re-crushing characteristics of graded gangue directly determine the quality and effect of filling the quarry. Firstly, the lateral limit uniaxial compression tests of continuously graded and discontinuous graded gangue were carried out by the hierarchical loading method. Based on the test results,the changes of compaction deformation parameters and re-crushing parameters under the influence of axial stress and gradation were studied, and the particle size distribution and fractal characteristics of the re-broken particles were analyzed. Then, based on the evolution of gradation compaction-shatters-fractal, the relation between the increment of compactness and fractal dimension, which respectively represent the characteristics of compaction and fractal, and the relation between the strain and the increment of fractal dimension, which respectively represent the characteristics of compaction and rebreakage, were established. The physical significance of the parameters in the relation was demonstrated, and the internal relation between the compaction and rebreakage of gradation gangue was discussed. The results show that, according to the change law of compression modulus and the mechanism of compaction deformation at different stages, the compaction stage of crushed gangue with different grades can be divided into three stages: rapid compaction, slow compaction and stable compaction. The particle size distribution characteristics after re-crushing indicate that the re-crushing of particles mainly occurs in the slow compaction stage. The proposed formula can well describe the whole process of compaction and recrushing of graded crushed gangue, which can reflect the stability of gangue with different levels in the process of compaction and re-crushing, and provide a theoretical basis for accurate filling and prevention of goaf.
作者
张天军
王小军
庞明坤
张硕
王飞
ZHANG Tianjun;WANG Xiaojun;PANG Mingkun;ZHANG Shuo;WANG Fei(College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;College of Science,Xi'an University of Science and Technology,Xi'an 710054,China;Shaanxi Binchang Wenjiapo Mining Company Limited,Binzhou 713504,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第1期314-326,共13页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51774234,51874234)
陕西省自然科学基金资助项目(2021JM-390)。
关键词
连续级配
间断级配
破碎矸石
压实
粒度分形
continuous gradation
discontinuous gradation
crushed gangue
compaction
granularity fractal
