Theoretical Calculation and Experimental Analysis on Initial Shock Pressure of Borehole Wall under Axial Decoupled Charge

Table 7

The charging parameters.

Axial decoupling coefficients	Hole length (cm)	Stemming length (cm)	Air column length (cm)	Charge length (cm)
				Total length (cm)	Upper length (cm)	Lower length (cm)
2.5	40	5	21	14	4.7	9.3
3.5	40	5	25	10	3.3	6.7
4.0	40	5	26.25	8.75	2.9	5.85
5.0	40	5	28	7	2.3	4.7
6.0	40	5	29.16	5.84	1.95	3.89