Abstract:Gas-containing coal is a two-phase dielectric composite material with porous characteristics and solid-gas coupling characteristics. In order to accurately simulate the physical and mechanical properties of gas-containing coal, based on similarity criteria and similarity scales of main control parameters, with more than 80 sets of material matching tests and mechanical parameter tests, a similar material for coal-gas two-phase medium was developed. The similarity between similar materials and raw coal was compared, and based on the new material, a three-dimensional simulation test of coal and gas outburst was performed. The main conclusions were as follows. 1) The elastoplastic parameters and adsorption parameters of new material prepared by pulverized coal and sodium humate aqueous solution as aggregate and binder is similar to raw coal. Similar materials with different elastic-plastic parameters can be prepared by adjusting the material ratio. The adsorption of similar materials is consistent with that of raw coal. 2) The expansion energy of the binary mixture of CO₂ and N₂ is between CO₂ and N₂. The proportional coefficient of expansion energy and CO₂ volume fraction are quadratic functions. The expansion energy of the mixture with 45% CO₂ volume fraction is consistent with that of CH₄. The binary mixture of CO₂ and N₂ can be used as similar gas to CH₄, and it is safer than CH₄. 3) The new material is highly similar to the physical and mechanical parameters of raw coal containing gas, which realizes the simulation of gas-solid coupling characteristics. 4) A three-dimensional physical simulation experiment reproduces the phenomenon of outburst caused by uncovering coal, and the morphology of outburst holes and the quality of outburst pulverized coal that are close to the field are obtained, which verifies the rationality of similar materials, and also provides a scientific means for further study of the law of outburst and monitoring the precursor information of outburst.