Investigation on Surrounding Rock Stability Control Technology of High Stress Roadway in Steeply Dipping Coal Seam

Table 3

Speculates the distance between the roof of the 12032 tailgates and the upper coal seam.

Distance to open-off cut L (m)	0–40	40–155	155–230	230–325	325–390	390–660	660–690
Roadway length l (m)	40.0	115.0	75.0	95.0	65.0	270.0	30.0
Roof thickness H (m)	2.20–2.50	2.50–2.80	2.00–2.50	2.50–3.20	2.20–2.50	2.50–3.50	3.50–3.70
Roof classification type	II	II	II	III	II	III	IV