Rock Load Estimation in Development Galleries and Junctions for Underground Coal Mines: A CMRI-ISM Rock Mass Rating Approach

Table 3

RMR and rock load estimation for galleries and junctions for different mines.

S. number	Name of the mine	Density; (t/m^3)	RMR	Rock load in gallery; (t/m^2)	Rock load in junction; (t/m^2)
For 3.6 m gallery width where roof rock density varied from 2.2 t/m^3 to 2.4 t/m^3; % variation of RMR and density from minimum value is up to 9.6% and 9.5%, respectively
1	Huriladih	2.19	57.6	1.83	2.89
2	Block IV	2.21	60.3	1.56	2.55
3	Sudamdih	2.4	61.2	1.59	2.65
4	Huriladih	2.23	55.8	2.07	3.19
For 4.2 m gallery width where roof rock density varied from 1.27 t/m^3 to 2.55 t/m^3; % variation of RMR and density from minimum value is up to 75% and 87.5%, respectively
1	Bagdighi	2.55	62.05	1.86	2.82
2	Jogidih	2.38	61.2	1.85	2.76
3	Khas Kusunda	2.18	58.7	1.99	2.86
4	Khas Kusunda	2.32	63	1.59	2.44
5	Damoda	2.4	61.2	1.86	2.77
6	Sendra Bansjora	2.05	55.8	2.22	3.07
7	Dobari	1.82	60.4	1.49	2.19
8	Tetulmari	2.37	60.8	1.88	2.8
9	Sendra Bansjora (Bot)	1.43	38.07	3.49	4.22
10	Gopalichack	1.48	43.3	2.94	3.66
11	Kusunda	1.36	36.7	3.49	4.19
12	Bagdighi	1.36	40.8	2.9	3.66
13	East Bhuggatdih	1.52	42.4	3.13	3.88
14	Damoda (BJ Pit)	1.27	36	3.34	4
15	Amlabad	1.44	41.6	3.06	3.78
16	Alkusha	1.49	43.2	2.97	3.69
17	Nichitpur	1.54	42.4	3.17	3.93
18	Industry	1.41	36.9	3.59	4.32
19	Ramkanali	1.44	41.6	3.07	3.78
20	Mudidih (Pit number 3)	1.51	43.74	2.94	3.67
For 4.8 m gallery width where roof rock density varied from 1.35 t/m^3 to 2.4 t/m^3; % variation of RMR and density from minimum value is up to 51.4% and 76.4%, respectively
1	Godhur	1.48	45	3.2	3.5
2	South Balihari	1.39	42.4	3.27	3.6
3	Huriladih	1.35	41.6	3.28	3.6
4	Godhur incline	1.47	43.2	3.35	3.8
5	Mahamaya mine, SECL	1.9	61.2	1.58	2.2
6	Churcha mine, SECL	2.4	56.7	2.82	3.6
7	Shivani mine, SECL	2.15	57.6	2.4	3.0
8	Baherabad mine, SECL	2.26	63	1.76	2.4