Study on the effect and control of the pressure relief borehole on anchor cable

Borehole pressure relief is an important means of shock resistance for rockburst roadways, but the boreholes will damage the roadway surrounding rock and affect the supporting environment. In order to study the influence of pressure relief boreholes on roadway support, based on the on-line monitoring system, the anchor cable stress after drilling pressure relief is monitored, and the anchor cable stress is simulated by 3DEC. The results show that with the advance of heading face, the anchor cable stress increases in sawtooth vibration at the initial stage, and finally increases slowly and steadily; when the heading face advances 20 m after installing anchor cable, the stress of the 3 anchor cables increases obviously, the closer to the heading face, the greater the increase of the anchor cable stress; compared with that before construction of pressure relief boreholes, the change of anchor cable stress after construction pressure relief boreholes is small, and the orifice part decreases slightly; pressure relief boreholes have little effect on plastic zone of surrounding rock, and only some scattered plastic yield points are formed on the hole wall; the influence of pressure relief boreholes on bolt mesh support can be better solved by filling with bag hole sealer within 2 m of the orifice of pressure relief borehole.