Grouting Reinforcement Mechanism and Multimodel Simulation Analysis of Longwall Goaf

Table 2

Observation of the depth statistics of borehole fracture development.

Drilling serial number	Depth of fissure development (m)	Detection depth (m)	Proportion of fissure (%)
4	31.0~38.5, 65.5~74.5, 128.5~130, 157.7~159.2, 162.2~163.7, 187.7~197.7, 234.2~237.2	28.0~245.4	15.6
8	40.5~45, 52.5~57, 64.5~70.5, 96~97.5, 100.5~102.0, 167.1~168.6, 170.1~177.6, 191.1~200.1	40.5~230.0	19.0
18	85.4~88.4, 89.9~92.9, 95.7~100.7, 113.7~116.7, 122.7~125.0, 128.7~134.7, 142.7~149.7, 169.7~175.7	85.4~193	32.8