电磁辐射在煤矿冲击地压预测中的应用外文文献翻译、中英文翻译.docVIP

英文原文 Calculation of Electromagnetic Radiation Criterion for Rockburst Hazard Forecast in Coal Mines V. FRID Abstract——Intensive micro-fracturing of rock close to mining operations accompanies an increase in the likelihood of rockbursting. This fracturing causes an increase of the electromagnetic radiation (EMR) level by up two orders of magnitude, depending on the mining environment. Several examples of this enhanced EMR are presented in this paper. We first treat the EMR theoretical criterion of rockburst hazard in coal mines and compare it with the empirical criterion of EMR activity that was revealed on the basis of more than 400 dilTerent hazardous and non-hazardous situations in underground coal mines. Only the following parameters are needed to estimate the EMR criterion of rockburst hazard: limiting value of gum volume, mine working width, coal seam thickness, and coal elastic properties. Key words: Rockburst, electromagnetic radiation, fracture, coal mines 1. Introduction The phenomenon of rockbursting has long been known in mining. The rockburst hazard increases if the load on a given part of a coal seam exceeds some critical level,while the distance to the stress maximum in the zone of influence of a mine working is lower than the critical value (PETUKHOV and LINKOV, 1983). The rockburst hazard is usually determined by some standard geomechanical method, for example, gum volume measurement, measurement of hole diameter or number of disks that are created due to core fracturing as a result of drilling in a highly stressed zone, etc. (PETUKHOV, 1972). The method of gum volume measurement is generally used in coal mines of the former USSR. All of these methods are very time-consuming and sometimes dangerous becausedrilling is required. For these reasons, rockburst hazard forecasting at a mineworking face must be made short-term and safe. Geophysical methods can help toreduce the risks (FALLON et al., 1997