The Effect of Joint Damage on a Coal Wall and the Influence of Joints on the Abutment Pressure on a Fully Mechanised Working Face with Large Mining Height

Table 1

The influence of the number of joints on the damage variable of coal containing through-going joints.

	Dip angle of joints (°)
Number of through-going joints	30	45	60	75
1	0.37	0.38	0.35	0.37
2	0.54	0.55	0.52	0.54
3	0.64	0.65	0.61	0.63
4	0.70	0.71	0.68	0.70
5	0.75	0.76	0.73	0.74
⋮	⋮	⋮	⋮	⋮
10	0.86	0.86	0.84	0.85
⋮	⋮	⋮	⋮	⋮
20	0.92	0.93	0.91	0.92
⋮	⋮	⋮	⋮	⋮
100	0.98	0.98	0.98	0.98