Abstract:
Real-time axial load of anchor bolts in mining-disturbed roadways for about 100 m zone just from the cutting holes outside 1321(3) working face in Dingji Coal Mine were intensively monitored by nondestructive testing. The monitoring results show that the axial load of bolts in the zone of 0 m to 20 m from the working face is varied violently by the heavy mining disturbance. The axial load of anchor bolt located in the zone of 0 m to 10 m is decreased. The lead abutment pressure zone is located in about 10 m to 20 m and its peak value occurs at nearly 15 m from the working face. The axial load of bolts in the zone above 20 m away from the working face is not varied violently by a little mining disturbance. The abnormal section of roadways or hidden fault zone was easily found by the intensive monitoring of axial load for anchor bolts.