Evolution law of surrounding rock bearing circle and support technology of deep roadway

Abstract

Taking Guotun Coal Mine -670 auxiliary horizontal track roadway as the engineering background, the stress change of roadway surrounding rock is analyzed through the mechanical model of bearing circle, and the stress change of roadway surrounding rock under different driving distances, lateral pressure coefficients and vertical stresses is studied by FLAC3D software. The resales show that as the roadway expands to the deep, the bearing ring also shifts to the deep and the thickness increases, the stress of the roof and floor of the roadway changes greatly than that of the two sides, and the shape of the bearing ring changes from circle to ellipse; the control effect of bolts and anchor cables with different lengths on the bearing ring is analyzed; the bolts mainly control the inner boundary of the bearing ring to reduce the damage of the shallow part of the roadway surrounding rock, and the anchor cables mainly control the outer boundary of the bearing ring and affect the stress distribution of roadway surrounding rock. According to the bearing ring theory and the control effect of bolt and anchor cable on the bearing ring, the combined support scheme of “bolt net shotcrete + bolt + anchor cable” is proposed. The application show that the combined support technology of “bolt net shotcrete + bolt + anchor cable” has great technical advantages for the control of surrounding rock in deep roadway.

Keywords

• deep roadway
• bearing circle
• stress variation
• numerical simulation
• combined support