MONITORING AND ANALYSIS OF FRACTURE DEVELOPMENT IN PRE-SPLITTING HOLE OF CAVE INDUCEMENT OF ROOF
顶板诱导崩落预裂钻孔裂隙发育监测与分析

Based on continuous mining technology, cave inducement of roof is a nontraditional, safe and high-efficiency method, which is widely used in mining of inclined, gently inclined large-scale barren orebody and processing technique to mined stope. In order to study the relationship between the evolvement of fracture and discontinuity in rock mass and mechanism of cave inducement of rock mass, the monitoring on development of fracture on the wall of pre-splitting boreholes in cave inducement of roof is put into practice by panoramic borehole television. According to monitoring results, the development situation of original fracture and discontinuity in rock mass under the artificial disturbance is reflected by the images. Consequently, a qualitative and intuitional evaluation to cave inducement can be provided; and the controllability of cave inducement roof is increased. The monitoring and analytical results show that a fractured zone comes into being in the range of 5 m in the direct roof during the cave inducement process. Relatively, the surrounding rock represents fragmentation circumstance. A ring-shaped fracturing zone is formed in the range of 10 m from the roof simultaneously. Then, with the farther development of quantity and density of fracture, the cave inducement of roof is formed ultimately.