Research on Formation Mechanism and Evolution Pattern of Bed Separation Zone during Repeated Mining in Multiple Coal Seams

Table 1

Rock stratum histogram.

No.	Lithology	Legend	Buried depth (m)	Thickness (m)	Bulk density (KN/m^3)	Elastic modulus (GPa)	Tensile strength (MPa)	Remarks
1	Coal 3		297.0	4.2	14.35	3.24	0.28
2	Limestone		295.1	1.9	24.00	5.53	2.06
3	Mudstone		285.5	9.6	25.50	3.05	1.57	KS1
4	Siltstone		282.2	3.3	24.90	9.09	6.40
5	Medium sandstone		277.5	4.7	24.70	13.25	4.00
6	Fine sandstone		274.7	2.8	24.80	16.45	4.65
7	Medium sandstone		260.0	14.7	24.70	14.24	4.00	KS2
8	Mudstone		253.8	6.2	25.50	3.05	1.57
9	Coarse sandstone		246.0	7.8	24.67	10.84	3.26
10	Coal 2		240.0	6.0	14.35	4.24	0.35
11	Fine sandstone		237.5	2.5	24.80	16.45	4.65
12	Coarse sandstone		231.5	6.0	24.67	10.84	3.26
13	Mudstone		223.5	8.0	25.50	3.05	1.57
14	Siltstone		219.5	4.0	24.90	9.09	6.40
15	Coal 1		216.5	3.0	14.45	4.24	0.14
16	Siltstone		206.5	10.0	25.00	9.12	6.40	KS3
17	Mudstone		202.5	4.0	25.50	3.05	1.24
18	Siltstone		192.3	8.2	24.90	9.09	6.58
19	Fine sandstone		184.3	8.0	24.80	16.45	4.56
20	Medium sandstone		180.3	4.0	24.70	14.24	4.54
21	Siltstone		165.3	15.0	24.90	9.09	6.95	KS4