循环载荷下矿山固废胶结充填体损伤过程声发射特性研究

To increasing recovery rate of resource，using artificial pillar which maded by tailings and waste rock for invironmental protection as substitute for ore pillar as the main loading structure in rare noble metals underground mine is a trend．It is a major threat to mining while the cemented filling was destroied under complicated mining circumstance．Wherefore，the mechanical property and damage mechanism in complicated mining circumstance of fill material was the precondition to choose．It is well known that the damage process of rock and concrete could be analyzed by acoustic emission．But the study on acoustic emission of cemented fill is still at an elementary stage now，which lack of the quantitative relation between them．This item draw up to reveal the damage and failure mechanism of cemented fill by using acoustic emission under cyclic loading test，then establish the celebrity quantitative relation between acoustic emission and the damage of cemented fill．All the research will provide the fundamental basis for forecasting the failure of cemented fill of mine．

为提高资源回收率，稀有贵重金属矿山地下开采多采用人工矿柱代替原生矿柱作为主要承载结构，鉴于矿山环保，人工矿柱多由尾砂和废石等矿山固体废料配入胶结材料形成，在井下回采复杂的外部力学环境下，一旦其破坏或失稳，将对安全回采形成严重的威胁。因此，固废胶结充填体在复杂环境下力学性能及损伤机理的研究是充填材料选择、优化与稳定性分析的重要依据，而声发射可以表征岩体及混凝土等脆性材料损伤过程，但目前对矿山固废胶结充填体声发射特性的研究刚处于起步阶段，尚缺乏胶结充填体损伤破坏与声发射之间定量关系的相关研究。本项目拟根据胶结充填体承受载荷的力学路径，进行循环载荷作用下矿山固废胶结充填体损伤过程声发射特性试验及相关理论研究，旨在反映工程实际力学路径，利用声发射揭示充填体损伤破坏机理，建立胶结充填体声发射参数与损伤二者之间的量化关系。为矿山现场固废胶结充填体承载过程分析及破坏失稳预测提供基础研究依据。

针对目前矿山作为主要承载结构的固废胶结充填体所采用的不同材料，本项目进行了不同骨料（即尾砂、废石）固废胶结充填体在循环载荷下损伤过程声发射特性试验及相关理论研究，利用声发射技术识别废石胶结充填体损伤过程，建立声发射表征废石胶结充填体损伤量化关系，通过声发射参量识别不同废石含量胶结充填体破坏模式。尤其是对尾砂废石所形成的固废胶结充填体承载损伤过程声发射所表现出的不同规律进行定量分析，寻找声发射参数与固废胶结充填体损伤的关系，在试验及理论研究基础上寻求尾砂、废石胶结充填体损伤破坏的声发射定量判据。研究表明：循环载荷下废石、尾砂和胶结面破坏过程声发射频率和能量特征存在明显差异，块石含量增加对胶结充填体前期损伤具有较好的抑制作用，声发射速率参数a值可有效识别固废胶结充填体破裂模式。研究成果对揭示矿山固废胶结充填体损伤机理，确定充填体损伤破坏定量判据具有重要的科学意义，同时为地下开采固废胶结充填体承载及损伤破坏过程的声发射监测、预测提供重要的基础研究数据。