Analysis On Mining Method And Roof Stability Under Condition Of Transform From Large Height Mining To Top Coal Mining

Aiming at the failure of roof carving and spalling in the higher mining process in coal4-2of Bu’ertai mine, this article proposed the ideas of transfer of fully mechanized mining to caving mining to in a plate area.The main contents are as follows:It is probed that the distribution of inside the plastic zone, the stress and displacement fields in roof(coal) when the carving height varies in higher fully mechanized mining.The analysis of range elastic-plastic zone when the top coal caving mining is used in coal4-2and determent of the slope and intercept range boundary range is made.Mechanical model of the two blocks fall under different shapes in top coal fissures is established,analyzing control method and control parameter for the end face plate (coal).Making the analysis mechanical about adaptability of two pillar caving hydraulic support, arguments put forward recommendations to optimize stent. The numerical simulation for caving face mining process control parameters is made, draw reasonable control range. The industrial practice has proved that two pillar caving hydraulic support could be adapted to the mining in this plate.