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

Table 1

Stratification and mechanical parameters of overlying strata in coal seam.

Layer number	Lithology	Cumulative depth (m)	Layer thickness (m)	Bulk density (KN/m^3)	Tensile strength (MPa)	Elastic modulus (GPa)
1	Topsoil	4.8	4.8	13.8	—	—
2	Gravelly sand	28.98	23.18	24	—	—
3	Glutenite	48.98	20	26.2	1.4	5
4	Sandy mudstone	54.67	5.69	25.5	1.0	3
5	Glutenite	81.97	27.3	26.4	1.6	5.1
6	Coal	85.04	3.07	14	0.84	2
7	Glutenite	107.01	21.97	26.4	1.7	5.2
8	Coal	109.01	2	14	0.82	2
9	Sandy mudstone	124.01	15	25.8	0.9	3
10	Coal	126.51	2.5	14	0.85	2
11	Sandstone	135.31	8.8	26.2	1.8	10.4
12	Glutenite	139.51	4.2	26.4	1.5	4.8
13	No. 6 coal	154.51	15	14	0.85	2