| China’s coal resources account for more than half of the world’s coal industry.With the development of industrialization,the demand for coal resources is higher and higher,and the mining scale and mining depth are also expanding,resulting in frequent mine earthquakes and more frequent rockburst accidents,causing certain property losses and casualties to the mining industry.Therefore,it is necessary to study and give early warning to mine earthquakes and rockburst.Effective prevention of rockburst is of great significance to coal mine safety production.The geological structure of Hegang is complex and there are many coal resources in the area.In recent years,the mine earthquake monitoring network and SOS microseismic monitoring system have been set up.Taking the mine earthquake and microseismic data of the working face as an example,the distribution characteristics in Hegang area have been found out.At the same time,the close relationship between mine earthquake,microseismic and rockburst pressure has been explored,and the early warning method of impact risk has been established through mine earthquake and microseismic parameters,which has been verified in practice,Finally,good prediction results are obtained.Based on the mine earthquake and microseismic data of a mine in Hegang,this paper analyzes the geological structure characteristics and mine earthquake activities in Hegang area in recent years,and determines the site category of Hegang Mining Area as class I site by Horizontal-to-vertical spectral ratio method,so as to provide reference basis for rockburst early warning later.Secondly,it explains the difference between mine earthquake and microseism,and distinguishes natural earthquake,mine earthquake,microseism and blasting through the monitored waveform time.This paper analyzes the composition,monitoring content,instrument composition,characteristics and accuracy of mine seismic network,and explains the current network layout and station selection in Hegang Mining Area.The necessity,instrument composition,monitoring mode,monitoring content,monitoring accuracy and layout principle of microseismic SOS monitoring system are explained.The mine seismic network and microseismic SOS monitoring system are compared from these aspects.This paper analyzes the mine earthquake events monitored in Hegang coal mine,analyzes the quantity and energy distribution characteristics of microseisms from the perspective of time and space,and analyzes the correlation between microseismic events and rockburst according to the maximum energy of microseismic day.This paper analyzes the distribution characteristics of the number and magnitude of mine earthquakes from the perspective of time and space,and briefly analyzes the activity of mine earthquakes.Then,it analyzes the magnitude and frequency changes 7 days and30 days before mine earthquakes from the perspective of qualitative and quantitative,explores the correlation between mine earthquakes and rockburst,and then connects mine earthquakes with microseismic events to analyze whether there is an internal relationship.Based on the quantitative analysis of the mine earthquake and microseismic data 7and 30 days before the impact,three corresponding precursor response indexes of mine earthquake are obtained:the dynamic frequency of mine earthquake,the frequency of mine earthquake M_L≥3,and the frequency of mine earthquake 2≤M_L<3.There are two corresponding microseismic precursory response indexes:microseismic frequency deviation and microseismic energy deviation.As a new index,it is introduced into the improved analytic hierarchy process and unascertained measurement theory.At the same time,geological factors,mining factors and management factors are considered to enrich the impact risk prediction index system.According to the comprehensive analysis method of improved analytic hierarchy process and unascertained measurement theory,a more scientific impact ground pressure early warning system is established. |
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