Design of outburst experiment device based on similar simulation and geomechanical model test and its application

Domestic and foreign scholars have made a lot of research on the process and mechanism of coal and gas outburst. Briquette was always used to test, but these tests rarely considered the influence of geological structures on outburst, and the data monitoring did not include the coal inside. On the basis of thoughts of the similar stimulation experiment and new ideas of the model test of geological mechanics, the experimental platform of coal and gas outburst for large coal uncovering by cross-cut in the laboratory was built. The geostress, gas pressure and structure of coal were considered. The test platform included test case, counter force frame, hydraulic loading system, sealing system and test monitoring system. Meanwhile, the line charging and plane charging system were designed to simulate the difference of gas in the coal seam. At the same time, the similar simulation test of tectonic soft coal uncovering by cross-cut was conducted in the laboratory. The variation laws of stress and displacement in the process of tectonic soft coal uncovering by cross-cut were studied. The gas pressure and acoustic emission in the process of outburst were also determined. The results show that the obvious stress concentration exists in surrounding rock ahead working face in the process of tunnel excavation. The closer to the tectonic soft coal is, the more obvious the stress concentration is. The displacement mutates near outburst point at the moment of outburst. Acoustic emission signal reduces once before outburst. The stress release of coal and rock in front of heading face provides the conditions for the crack increase and the rapid diffusion of gas.