Study on the Development Height of Overburden Water-Flowing Fracture Zone of the Working Face

Table 2

Calculation parameters of layer elongation rate.

Rock layer	Height of rock intermediate layer (m)	Cot	Cot	Mining thickness (m)	Bulking coefficient of rock layer	Maximum subsidence of rock layer (m)	Layer elongation rate
No. 5 mudstone	8.64	0.577	0.577	8.70	1.14	5.92	22.07%
No. 7 mudstone	15.49	0.577	0.577	8.70	1.13	5.16	5.54%
No. 9 mudstone	22.99	0.577	0.577	8.70	1.12	4.60	2.15%
No. 11 mudstone	30.84	0.577	0.577	8.70	1.11	3.64	0.70%
No. 13 mudstone	34.24	0.577	0.577	8.70	1.11	3.33	0.53%
No. 15 mudstone	42.44	0.577	0.577	8.70	1.11	2.56	0.12%
No. 17 mudstone	49.99	0.577	0.577	8.70	1.10	2.18	0.09%