A large-scale three-dimensional coal and gas outburst quantitative physical modeling system

Coal and gas outburst quantitative physical modeling under a variety of conditions has become the main method to reveal the mechanism of coal and gas outburst.Based on the CSIRO outburst model and combination theory hypothesis, according to similarity criterion, a large-scale true three-dimensional coal and gas outburst quantitative physical modeling system was developed, which can consider the possible combina-tions of geologic setting, geo-stress, coal density, gas pressure and construction process.The system consists of five key units: model counter-force apparatus and seal space unit, high geo-stress gradient loading and control unit, mass flow and high pressure gas filling unit, tunnel micro-TBM (Tunnel Boring Machine) and high-speed recording unit, and multi-information instantaneous acquisition unit.The system with the maximum model size of 1.5 m×1.5 m×3 m (long×width×thick) was developed, and the maximum loading capacity was 60 MPa, which could achieve the true 3 D gradient loading, the thickness direction ofmodel could be adjusted by a multiple of 0.6 m, and the maximum inflating pressure was 3 MPa.The maximum acquisition frequency of micro fiber grating sensor was 500 kHz and the maximum excavation speed of laneway was 10 cm/min.The units work together to simulate the coal and gas outburst of rock cross-cut coal uncovering in the gas-solid coupling and three dimensional loading conditions, providing a quantitative simulation platform for researching the outburst occurrence conditions in different factor combinations and revealing the coal and gas outburst mechanism.