声发射监测技术用于采空区地压灾害预测

东河湾铁矿经过多年开采,存在采空区多、滞留时间长、安全隐患大等问题。为了在采空区发生重大地压灾害前能够提前预警,以便采取必要的安全措施,预防采空区重大灾害发生,须建立预警预报系统。以岩石力学试验及采空区有限元稳定性分析为基础,分析最易发生重大灾害的区域,确定必要的监测范围。选用国内先进的STL-12型声发射监测系统,针对危险区域建立了完善的声发射在线实时监测体系。利用室内声发射试验以及现场震动波形实测,构建了岩石声发射及其他震动波形库,总结了该矿岩石破坏过程的声发射特征。通过波形分析及时掌握了采空区围岩地压活动的声发射信息变化规律,制定了完善的预警预报制度。近2 a的现场实践表明,该系统可为东河湾铁矿采空区塌陷的预测预警提供技术支撑。

Application of Acoustic Emission Monitoring Techniques in Geostress Hazard Prediction of Mined-out Areas

After many years exploration in Donghewan Iron Mine，complex mining status appears，such as lots of mined-out areas，long remained time，and big security risk. In order to make early-warning before the geo-stress disasters occur in the mined-out area to take necessary security measures and to prevent major disasters，the early warning and forecasting system was established. Based on the rock mechanics test and the finite element stability analysis on mined-out area，the regions that are prone to generate major disasters are analyzed and the necessary monitoring scope is determined. With the selection of the advanced STL-12-type acoustic emission monitoring system，a complete acoustic emission on-line real-time monitoring system for hazardous areas is built. According to the indoor acoustic emission testing and on-site vibration waveform measurement，the rock acoustic emission database and other vibration waveform database are established，and the acoustic emission characteristics during the destruction process of rocks are summarized. By waveform analysis，the variety rule of acoustic emission information at geostress activities of mined-out area is grasped，and a comprehensive early warning and forecasting system is made. The 2-year practice showed that the system could provide technical support for pre-warning of mined-out subsidence in Donghewan Iron Mine.