Roof Movement and Failure Behavior When Mining Extra-Thick Coal Seams Using Upward Slicing Longwall-Roadway Cemented Backfill Technology

Table 2

Allowable tensile stress and bending moment of the roof for different slices.

Slice number	1	2	3	4	5	6
Allowable tensile stress of the roof (MPa)	2.2	2.2	2.2	2.2	2.2	4
Allowable bending moment of the roof (N·m)	1.12E8	7.19E7	4.04E7	1.80E7	4.50E6	4.00E8