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 2

Occurrence of joints with different parameters in coal seam.

Serial number	Properties of joints	Parameters of joints			Remarks
		Dip angle α (°)	Azimuth β (°)	Spacing d (m)
1	Primary joint	45	0	5	A model
2		90			B Model
3		135			C Model
4		45	45		D model
5			135		E model
6	Primary joint	90	0	2	F Model
	Secondary joint	45
7	Primary joint	90		2	G model
	Secondary joint	45		1.41
8	Primary joint	90		2	H Model
	Secondary joint	135
9	Primary joint	90		2	I Model
	Secondary joint	135		1.41

Note: The dip angle α of joints refers to the included angle between the dip direction of joints and the Y-axis positive direction (advancing direction) in 3DEC software; the azimuth β denotes the included angle between the strike direction of joints and X-axis positive direction (the direction along the length of the working face).