摘要
破碎矸石在压缩过程中的侧压系数是固体充填沿空留巷工作面巷旁支护体设计的关键参数。然而以往研究中大多使用经验参数,与现场实际情况差别较大。基于此,本文在破碎矸石压缩试验的基础上,采用颗粒流数值模拟软件,通过三维扫描重构矸石颗粒并建立数值模型,确定破碎矸石颗粒流细观参数,并研究颗粒级配、加载速率对破碎矸石压实特性和侧压系数的影响规律。结果表明:破碎矸石压实过程可分为初始压密阶段、承载能力增长阶段和应力-应变线性阶段3个阶段;破碎矸石侧压系数随着压实的不同阶段不断增长,在应力-应变线性阶段趋于稳定,稳定值在0.35~0.40;加载速率增高,能够提高破碎矸石早期承载能力,同时降低早期侧压系数,但在应力-应变线性阶段加载速率对破碎矸石压实特性影响较小;矸石颗粒级配中粒径较高时,矸石轴向承载能力降低,同时侧压系数降低。研究成果可为充填开采无煤柱沿空留巷参数设计提供理论依据。
The Lateral Pressure Coefficient(LPC) of the crushed gangue is an important parameter in the design of support body of gob-side entry retaining with solid back-filling mining technology. However, the experience parameters used in previous studies are quite different from the actual situation. Based on this, with the compression tests of crushed gangue and particle numeral simulation software, the gangue particles have been reconstructed through 3 D scan and its numerical model has been established, the meso-structure mechanical parameters of crushed gangue has been determined, and the influence of particle composition and loading rate on the compaction characteristics and the LPC has been studied in this paper. The results have shown that the compaction process of crushed gangue is divided into three stages, i.e. initial compaction stage, bearing capacity growth stage, and linear stress-strain stage. The LPC of crushed gangue increases with different stages of compaction and this coefficient stabilizes at around 0.35-0.40 in linear stress-strain stage. As the loading rate increases, the early bearing capacity of crushed gangue increases, while the early LPC decreases. The effect of loading rate on the compaction characteristics of crushed gangue compaction is quite small in linear stress-strain stage. The axial bearing capacity of crushed gangue decreases and its LPC decreases when the particle size of crushed gangue is large. These research results can provide theoretical basis for the design of the parameters of the roadway along the goaf without coal pillars.
作者
肖猛
巨峰
何泽全
李开源
王鹏
XIAO Meng;JU Feng;HE Zequan;LI Kaiyuan;WANG Peng(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;College of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Shandong Xinjulong Energy Co Ltd,Heze,Shandong 274000,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2020年第1期73-80,共8页
Journal of Mining & Safety Engineering
基金
国家重点研发计划项目(2018YFC0604706)
江苏省研究生科研与实践创新计划项目(KYCX19_2172)
中国矿业大学研究生科研与实践创新计划项目(KYCX19_2172)。
关键词
采选充+
沿空留巷
侧压系数
颗粒流
mining-dressing-backfilling+
gob-side retaining
lateral pressure coefficient
particle flow code
