Deformation Rules for Surrounding Rock in Directional Weakening of End Roofs of Thin Bedrocks and Ultrathick Seams

Table 1

Ratio parameters of layered materials.

Rock layer name	Depth of stratum (m)	Model thickness (cm)	Sand (kg)	Calcium carbonate (kg)	Gypsum (kg)	Total mass (kg)
Glutenite	14.3	14.3	32.84	2.53	2.53	37.89
Basalt	5	5	11.59	1.32	0.33	13.25
Fine sandstone	2.6	2.6	5.97	0.64	0.28	6.89
Medium sandstone	20	20	44.16	4.42	4.42	52.99
Sandy mudstone	8.3	8.3	19.24	1.92	0.82	21.99
Fine sandstone	6.3	6.3	11.13	1.11	4.45	16.69
Conglomerate	15	15	35.77	3.18	0.79	39.74
Siltstone	5	5	10.60	0.79	1.85	13.25
Medium sandstone	1.1	1.1	2.55	0.11	0.26	2.91
Siltstone	6.7	6.7	15.02	1.91	0.82	17.75
Coal	16	16	37.09	2.12	3.18	42.39
Siltstone	10	10	22.42	1.22	2.85	26.50
Fine sandstone	2.6	2.6	4.59	0.69	1.61	6.89