Study on the Upper Limit of Roof Failure in Soft Rock Roadway

Table 6

Support parameters.

Programs	Classification	Diameter (mm)	Length (mm)	Spacing (mm)	Row spacing (mm)	Pretightening force (kN)
Program 1 (original program)	Roof bolt	22.0	2400	900	900	60
	Bolt in sidewall	20.0	2200	1100	900	60
	Anchor cable	18.9	7200	900	900	100
Program 2	Roof bolt	22.0	2400	900	900	80
	Bolt in sidewall	22.0	2400	900	900	80
	Anchor cable	21.6	8300	900	900	120