【摘要】 煤样损伤、变形与动态失稳之间具有内在的相关性,大尺寸煤样破坏试验成为分析采空区围岩动力失稳孕育过程的基础手段。西部的华亭煤矿曾发生过严重矿震,通过深入调查并精心选取不同尺寸煤样品,在圆柱体小煤样单轴压缩试验基础上,完成2个大尺寸(195mm×110mm×206mm,195.0mm×195.0mm×11.5mm)且结构与均匀程度不同(平行与垂直层理)的立方体煤样试件损伤、变形与破坏的声发射(acoustic emission,AE)特征试验,获得丰富的损伤演化信息,利用统计物理学且对连续场进行描述的态矢量原理定量地描述煤介质破坏的进程及其破坏程度,定义了损伤程度百分比,将其作为定量指标反映煤样局部损伤与破裂密集程度,对不同加载模式下煤介质损伤变形应力-应变与AE特征进行对比分析,为理论分析、数值模拟及提高动力失稳及采矿安全预报的时、空、强精度提供必要的条件。更多还原

【Abstract】 Deformations and damages of coal have intrinsic relativity with dynamic destabilization. The experiment on large size coal progressive fracture is a fundamental way to analyze the crack and evolution process of surrounding rock in the mined-out area. By in-situ comprehensive investigation and the well-chosen coal specimens of different sizes from the Western Huating Coal Mine where serious mining-induced seismicity occurs,based on the uniaxial test of some columnar and simple coal specimens,the acoustic emission(AE) characteristic experiments of two cube specimens of large size with different structures and heterogeneity(parallel and vertical lamination,the dimensions are 195.0 mm×110.0 mm×206 mm,195.0 mm×195.0 mm×11.5 mm respectively),are conducted under different loading models,and abundant information and parameters upon deformation and their evolution are acquired. The corresponding statistical physical parameter(state vector),which characterizes the continuous rough particle and spatial field is adopted in order to describe cracks and damages process of the coal media and their damage degree quantitatively. Furthermore,the damage degree percent is proposed as a quantitative index to characterize local damage and concentration of fractures. Finally,the comparative analysis between stress-strain and AE progressive characteristics are obtained. An essentialqualification is provided to theoretical analysis,numerical simulation so as to enhance the accuracy of temporal-spatial-relationship and intensity of dynamical unstable and safe mining prediction.更多还原