Experimental investigation on stress distribution and migration of the overburden during the mining process in deep coal seam mining

Geoenvironmental Disasters

Table 1 Rock layer simulation parameters and material ratio

Number	Name of rock layer	Thickness/cm	Ratio No.	Weight of each component material (kg)
Number	Name of rock layer	Thickness/cm	Ratio No.	Sand	lime	gypsum
9	Aluminum mudstone	14	864	44.8	3.36	2.24
8	Sandy mudstone	17	773	53.55	5.22	2.32
7	Coarse sandstone	5	775	16.35	1.20	1.20
6	Medium fine Sandstone	18	655	60	5.10	5.10
5	Medium sandstone	21	564	68.25	8.19	5.46
4	11 − 2 Coal	4.6	1055	8.78	0.44	0.44
3	Mudstone	4	864	6.40	0.48	0.32
2	Siltstone	6	955	21.04	1.18	1.18
1	Sandy mudstone	9	773	28.35	2.82	1.23