Stress relieving effect of non-coupling blasting technique on high stress area

To investigate the stress relieving mechanism and the effect of the non-coupling blasting on the high-stress area in a coal tunnel, we carried out theoretical analysis and laboratory experiment, followed by in-situ verification and numerical simulation. The results show that, in the laboratory experiment, although blasting can obviously relieve its stress in specimen, the existence of the hulking stress results in increasing the stress recovery rate after the blasting. Therefore a stress relieving method was proposed which combines blasting and pre-splitting drilling with discharging pulverized coal; the verification of the stress-relieving effect on the roadway sides in the high-stress area shows that the method can effectively reduce the high-stress concentration near the roadway.