Longwall Mining Stability in Take-Off Phase

Table 1

Properties of the materials in each section or span.

	Section 1; siltstone	Section 2; siltstone	Section 3; siltstone	Section 4; siltstone	Section 5; siltstone	Section 6; siltstone
Length of span (m)	1.25	1.25	1.25	1.25	1.25	1.25
Thickness (m)	1.5	1.5	1.5	1.5	1.5	1.5
Young’s modulus (MPa)	3550	3550	3550	3550	3550	3550
Load (kN/m)	17200	17200	17200	17200	17200	17200
Supporting stiffness (MPa/m)	47.8	47.8	47.8	47.8	47.8	47.8
Tensile strength (MPa)	4.24	4.24	4.24	4.24	4.24	4.24
Prop number	1		2		3
Prop stiffness (MPa/m)	1500		1500		1500
Spacing of props (m)	0.55		0.55		0.55