The influence of cutting roof parameters on stability of surrounding rocks under the condition of double cutting roof

Abstract

Taking 4502 working face of Shaqu No.1 Coal Mine as an example, the influence of roof cutting parameters on the stability of surrounding rock is studied by means of theoretical analysis, numerical simulation and field measurement. The results show that: the double roof cutting can weaken the stress concentration phenomenon inside the solid coal wall, which is beneficial to the stability of the surrounding rock of the roadway, but the larger the height of the roof cutting, the larger the vertical displacement of the roadway roof, which is not conducive to the control of the roof deformation. A certain angle of the roof cutting is beneficial to the collapse of the roof in the mining area, but the larger the angle of the cut roof, the larger the peak stress concentration and the value of the sinking of the roadway roof, which increases the difficulty of the anchor cable reinforcement. The height and angle of the roof cutting should be selected moderately, and the optimum value is 13 m and 15° respectively, when the oblique length of slit is 13.5 m, the results of field measurement and numerical simulation are in good consistency.

Keywords

• gob-side entry retaining
• double roof cutting and pressure release
• cut roof height
• cut roof angle
• surrounding rock stability