| As some coal mines in our country enter deep mining,under the conditions of high ground stress,high gas pressure and high gas content,the interaction between coal and gas outburst and rockburst dynamic disasters began to appear,which makes the occurrence mechanism of deep mine dynamic disasters more complicated and more difficult to prevent and control.Therefore,it is of great significance to study the related dynamic disasters of coal and gas outburst-burst pressure under deep conditions.This paper relies on the National Natural Science Foundation of China “Research on the Disaster Pregnancy Mechanism of Shock-Outburst Composite Power Disasters under the Influence of Deep Mining”,Chongqing Outstanding Youth Science Foundation ’s “Dynamic Instability Characteristics of Deep Well Coal and Rock Combination Structure and Its Gas-solid Coupling Mechanism Research " and China Coal Science and Technology Group Co.,Ltd.Science and Technology Innovation and Entrepreneurship Fund Special Project" Small Coal Rock Gas Complex Dynamic Disaster Small-scale Simulation Experimental Research ".Mainly using a combination of theoretical analysis and experimental research,a small test device for mechanical failure of gas-bearing coal-rock composite bodies and the energy evolution law analysis of the failure process of gas-bearing daily rock-body composite bodies are mainly carried out,and the following main results have been achieved:(1)A small experimental device for mechanical destruction of gas-bearing coalrock combination was developed.The whole process and real-time synchronous monitoring of the stress and strain of the rock part and the coal part during the destabilization and destruction of the gas-bearing coal-rock combination are realized.(2)Based on the preparation of similar coal outburst materials and its process,a briquette with high strength and good adsorption performance has been prepared.Its uniaxial compressive strength is 6.19 MPa ~ 6.58 MPa,and the initial carbon dioxide emission rate is 34 mmHg ~ 35mmHg(3)Carried out mechanical failure experiments of gas-bearing coal-rock combination under different roof lithology,rock-to-height ratio,loading rate and gas pressure,etc.,and tested the stress and strain changes of the rock,coal and combination in the coal-rock combination.After analyzing the influence of different influencing factors on the mechanical failure characteristics of coal-rock composites,it is found that after the mechanical failure of gas-bearing coal-rock composites reaches the peak,the rock exhibits the characteristics of "strain rebound and elastic energy release".This laid the foundation for further analysis of the "release path" and "release amount" of the coal roof combination and the surrounding rock system to release elastic energy in the deep high impact stope environment,which is beneficial to Deep well shock-outburst prevention and treatment of compound dynamic disasters.(4)The energy evolution of the coal-rock coal-bearing rock mass instability and failure process is analyzed.The energy density of the rock,coal body and each part of the rock mass is deduced and calculated.The effect of the accumulated elastic energy of rock on the mechanical damage of the rock mass is studied.The law of elastic energy released after rock peak in coal-rock combination under different conditions.The results show that under the action of gas,the energy transfer from the rock mass to the coal mass in the coal-rock combination is enhanced,and the energy dissipated by the destruction of the coal mass is weakened.This laid the foundation for further analysis of the "release path" and "release amount" of the coal roof combination and the surrounding rock system to release elastic energy in the deep high impact stope environment,which is beneficial to Deep well shock-outburst prevention and treatment of compound dynamic disasters. |
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