Borehole destressing mechanism and determination method of its key parameters in deep roadway

Based on the strength degradation law of surrounding rock obtained from some experimental data,the strain softening model in FLAC3D was improved by a secondary development. The mechanical parameters of surrounding rock were derived by an inversion method using the measurement data of mine pressure as characteristic values. This paper proposed the assessment index for the effectiveness of borehole destressing,and the classification criteria for destressing degree. Through a systematic study about the effects of borehole parameters (length,diameters and inter-row spacing) on the stability of surrounding rock of deep roadway,the paper put forward a method to determine the key parameters influenced by borehole distressing,and then improved the technical system of borehole distressing. The practical appli- cation shows that the application of the borehole schemes determined by the proposed method can control the surround- ing rock effectively. The method is simple to be mastered.