Numerical simulation of coal and gas outburst combining with acoustic emission research

摘要

The paper focused on numerical simulation of coal and gas outburst combining with acoustic emission technique, coal and gas outburst simulation experimental equipments with three dimensional stress loading system and PCI-2 acoustic emission monitoring system have been used. The results showed that: deformation and failure processes of coal sample containing methane under three dimensional stresses are composed of four stage, they are initial compression, elastic deformation, plastic deformation and failure. The developments of internal microcosmic fractures for coal sample containing methane are reflected by distribution law of acoustic emission events. It is found that deformation and failure zone for coal sample under three dimensional stresses was an ellipsoid zone. The primary acoustic emission events are generated at the weak structural surface with ease compressing of ellipsoid external. And then the events are gradually increased till outburst occurred. The results of numerical simulation displayed coal and gas outburst was affected by in-situ stress, gas pressure and coal mass physical and mechanical characteristics. The failure zone is similar to ellipsoid, the synthetically effect mechanism of coal and gas outburst is also illustrated.