Quantitative Characterization of Overburden Rock Development Pattern in the Goaf at Different Key Stratum Locations Based on DEM

Table 1

Physical parameters and tensile rate of each rock formation.

Layer number	Lithology	Strata thickness/m	Vertical height from coal seam roof/m	Tensile rate (%)
J17	Mudstone	5.3	100.6	0.11
J16	Sandstone	11.4	89.2	0.11
J15	Mudstone	4.5	84.7	0.13
J14	Sandstone	6.8	77.9	0.16
J13	Fine sandstone	5.6	72.3	0.18
J12	Medium grain sandstone	3.0	69.3	0.21
J11	Mudstone	5.1	64.2	0.24
J10	Sandy mudstone	15.2	49	0.34
J9	Mudstone	11.1	37.9	0.63
J8	Post office box stone	4.2	33.7	0.99
J7	Mudstone	5.8	27.9	1.43
J6	Medium grain sandstone	7.2	20.7	2.62
J5	Sandy mudstone	5.0	15.7	5.83
J4	Medium grain sandstone	6.7	9	20.63
J3	Sandy mudstone	3.0	6	2.81
J2	Coal seam	6.0	0
J1	Post office box stone	26.6	22.3