Study on distribution law of supporting pressure and plastic zone of coal pillar in strip mining

In order to study the distribution law of supporting pressure and plastic zone of coal pillar in strip mining, by means of theoretical analysis, numerical simulation and field monitoring methods, the supporting pressure distribution of coal pillar is determined by considering the arching effect of overlying coal and rock mass in goaf. Combined with the coal pillar supporting pressure distribution, according to the engineering conditions of Yuhua Coal Mine, the maximum plastic zone width of coal pillar with different goaf width (from 100 m to 260 m) and different working face buried depth (from 400 m to 600 m) was calculated by ANSYS15.0 simulation, and the maximum plastic zone of coal pillar with return airway in 2410 working face of Yuhua Coal Mine was monitored. The research results show that the maximum plastic zone width of coal pillar calculated by simulation is consistent with the field monitoring results according to the proposed calculation method of coal pillar supporting pressure.The calculation method to determine the supporting pressure distribution of coal pillar and the distribution law of the maximum plastic zone of coal pillar calculated by this method are given, which can provide a basis for the design of coal pillar width.