Application of Screw Bolts in Coal Roadway Support

In order to solve collapse and high installation failure rate problems of bolts holes drilling procedure during the period of broken surrounding rock support in Xiangshan Mine, screw bolts technology was introduced. Based on the analysis of structural characteristics and mechanism of the screw bolts, the pulling force has b een calculated theoretically. According to the trial results, theoretical values of anchors with different lengths had an average error ( 8%) compared to the practical one s. Moreover, the new screw bolts support technology was proposed and applied in the downdip hauling roadway of No.5 coal seam. The numerical simulation analysis r esults suggested that the rate of successful screw bolts installation was 95% and the resistance force increased fast. While the rock deformation was 5 mm, the anchori ng force had raised to about 33 kN. With further rock deformation, the rock displacement was less than 20 mm. These results indicated that screw bolt technology was effective to control the surrounding deformation of the coal roadway.