Monitoring and warning technology of acoustic emission in static loading rock burst of coal mine

Aiming at the problem of acoustic emission monitoring and warning of static loading rock burst,the author analyzes the acoustic emission response characteristics of the samples in the primary fracture closure stage,linear elastic stage,elastic-plastic deformation stage and strain softening stage from the relationship between the full stress-strain curve and acoustic emission frequency of laboratory coal and rock mass samples,and explains the principle of monitoring and warning technology in coal mine static loading rock burst monitoring,introduces the monitoring and warning technology of coal mine static loading rock burst based on energy change rate PE and frequency change rate PN,establishes the monitoring and warning model of coal mine static loading impact risk level,discusses the main influencing factors of the technology in coal mine field application,and designs the reasonable underground installation mode of acoustic sensor. Taking the monitoring and warning of acoustic emission during the excavation of transportation roadway in No.205 working face of a mine as an example,taking hour and work shift as the basic units,this paper constructs a static loading rock burst hazard level monitoring and warning model based on the frequency deviation,energy deviation and theirs duration of acoustic emission events. Main conclusions are as follows:①A small amount of acoustic emission events occur in the primary fracture closure stage and linear elastic stage,and a large number of acoustic emission events will be released from the stage of elastic-plastic deformation to the ultimate bearing capacity,which is the theoretical basis for monitoring and warning of static loading rock burst; ②The roadway side grouting,full-length anchoring,sound insulation cotton filling and other installation methods are adopted to reduce the background noise and improve the signal-to-noise ratio,distinguish the data between the production shift and the maintenance shift,and establish the construction information sharing mechanism,which can strengthen the manual elimination of production interference;③For the excavation construction of the transport roadway in No.205 working face of a mine,the acoustic monitoring system gives a warning of 19 hours in advance.