轴向动荷载作用下煤系石灰岩损伤特性研究  

Research on damage characteristics of coal-measure limestone under axial dynamic load

作　　者：杨东启 刘建庄 贺健宇[1,2] 张涛涛 闫闯 YANG Dongqi;LIU Jianzhuang;HE Jianyu;ZHANG Taotao;YAN Chuang(College of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China;Hebei Key Laboratory of Mineral Development and Security Technology,Tangshan 063210,China)

机构地区：[1]华北理工大学矿业工程学院,河北唐山063210 [2]河北省矿业开发与安全技术重点实验室,河北唐山063210

出　　处：《煤矿安全》2023年第2期107-112,共6页Safety in Coal Mines

摘　　要：为降低在巷道支护、掘进的过程中,工程扰动、爆破等活动对围岩稳定性的影响,开展煤系石灰岩在不同冲击荷载下的损伤特性研究;使用霍普金森压杆进行不同冲击荷载下的冲击试验,利用LS-DYNA有限元软件模拟石灰岩破碎过程,对破碎后各粒度质量分数、应力-应变曲线、峰值应力-平均应变率曲线及石灰岩破碎过程分析。结果表明:随着冲击荷载增大,峰值应力、平均应变率逐渐增大,试件破碎程度愈发严重,且峰值应力与平均应变率呈近似线性关系;不同冲击荷载下,试件破碎遵循由边缘向中心扩展、由内部裂隙间挤压破碎向外部发育的规律,其破坏过程分为裂隙闭合阶段、近似弹性阶段、裂隙急速发育阶段和快速卸载阶段;峰值应力、试件破碎程度以及试样破碎能量耗散受应变率影响显著。In order to reduce the influence of engineering disturbance, blasting and other activities on the stability of surrounding rock in the process of roadway support and excavation, the damage characteristics of coal measure limestone under different impact loads were studied. Hopkinson pressure bar is used to conduct impact under different impact loads. The crushing process of limestone was simulated by LS-DYNA finite element software, and the mass fraction of each particle size, stress-strain curve,peak stress-average strain rate curve and limestone crushing process were analyzed after crushing. The results show that with the increase of the impact load, the peak stress and average strain rate gradually increase, and the fracture degree of the specimen become more serious, and the peak stress and the average strain rate show an approximate linear relationship;under different impact loads, the fracture of the specimen follows the law that the edge expands to the center and develops from the internal cracks to the outside. The failure process is divided into the crack closure stage, the approximate elastic stage, the rapid development stage of the crack and the rapid unloading stage. The crushing energy dissipation is significantly affected by the strain rate.

关 键 词：霍普金森杆 LS-DYNA 石灰岩 损伤特性 应变率 轴向动载荷 

分 类 号：TD315[矿业工程—矿井建设]