Roof Failure Mechanism and Control Technology of Large Section Open-Off Cut in Soft Rock Strata with Thin Thickness

Table 1

Borehole imaging results.

Monitoring point	Number of broken areas	Crushing length/number		Maximum crushing area length (mm)	Crushing depth (main/maximum)
		>20 mm	>40 mm
1	12	5	3	72	<1.5 m/1.96 m
2	9	4	1	66	<1.8 m/2.37 m