Evaluation Of Impact Tendency Of Coal Samples And Study On Acoustic Emission Characteristics Of Loaded Damage

Coal and dynamic disasters,such as rock burst,threaten the coal mines production safety badly,which would cause damage to lanes and to personal injury and death.Along with the depth of mining exploitation increases yearly,its hazards become worsening.At present,it is of great difficulty to evaluate bursting liability of coal samples comprehensively.On the other hand,acoustic emission technology has become an important technical measure for rock burst prediction,but the comparative analysis and study on coal samples with different bursting liability under the uniaxial loading failure,the types of failure,the evolution of acoustic emission signals,and the fractal characteristics of acoustic emission signals,are not yet systematic.Therefore,this paper,will evaluate the bursting liability of the collected coal samples through distance discriminant analysis model,established,and then,study systematically the deformation and failure characteristics,and the law of acoustic emission evolution in the stage of crack initiation,propagation and penetration of coal samples with different bursting liability under uniaxial compression;will analyze the fractal characteristics and the evolution law of the correlation dimension of the acoustic emission signals from the uniaxial loading failure of coal samples with different bursting liability.The results show:The distance discriminant analysis model,with high accuracy,to predict the coal samples with different bursting liability,which was established,can make up for the shortcomings of the fuzzy comprehensive assessment method.And it is an effective method to predict bursting liability of coal samples.The sudden increase-calm-sudden increase of acoustic emission signals would appear before loading destruction of coal samples with different bursting liability,which can be used precursor of the information about the upcoming destruction of coal sample,besides,the precursory information of coal samples of strong,weak and no bursting liability occur in about 85%~90%,75%~78% and 51%~55% of the peak stress respectively.There are good fractal characteristics in AE counts of coal samples with differentbursting liability,during the process of uniaxial compression deformation and failure.The evolution of correlation dimension values has certain similarities during loading destruction of coal samples with different bursting liability: the correlation dimension values all experience an evolutionary pattern of fluctuating ascent and descent,which can be used as precursory information about the upcoming destruction of coal sample,too.The research results will form certain theoretical and practical significance in further improving the accuracy of AE prediction of coal and rock dynamic disasters such as rock burst,and ensuring the coal mines production safety.