Study on Overburden Stability and Development Height of Water Flowing Fractured Zone in Roadway Mining with Cemented Backfill

Table 2

Load of overlying strata and identification of key strata above coal seam.

Layer number	Lithology	Layer thickness (m)	Key stratum	Load (kPa)
2	Gravelly sand	23.18	—	—
3	Glutenite	20	—	1146.56
4	Sandy mudstone	5.69	—	145.1
5	Glutenite	27.3	Main key stratum	1621.85
6	Coal	3.07	—	42.98
7	Glutenite	21.97	Inferior key stratum	622.33
8	Coal	2	—	28
9	Sandy mudstone	15	—	414.31
10	Coal	2.5	—	35
11	Sandstone	8.8	Inferior key stratum	279.5
12	Glutenite	4.2	—	110.88