Rationality of Roof Cutting and Pressure Relief Parameters in Hard Roof Working Faces
In order to study the rationality of the roof cutting and pressure relief parameters in the hard roof working face,the production geological conditions of the 11#coal seam working face in Jiangjiawan Coal Mine were taken as the research object.Theoretical and numerical simulation analysis methods were used to provide and optimize the roof cutting parameters.The research results were as follows:based on engineering conditions and theoretical analysis,the cutting height was 11.4 m and the cutting angle was 1°-9°;combining theoretical calculations,it was found that the optimal pressure relief effect was achieved at a top cutting angle of 10°through numerical simulations;after roof cutting of the working face,the displacement of the face roof was larger than the displacement when the roof was not cut,the roof cutting effect in this state is relatively stable,and the stress of the working face after roof cutting decreased by about 20%,the stress concentration range of the working face expanded and extended deeper,and the squeezing effect of the goaf roof on the working face decreased;engineering experiments were conducted and observation stations were set up,which was found that the roof to floor convergence after cutting decreased by about 27%,and the force on the anchor rods decreased by about 24%,which meant that the phenomenon of stress concentration in the surrounding rock after top cutting was alleviated.
hard roofheight of roof cuttingangle of roof cutting3DEC simulation
NETL
NSTL
万方数据
