Design Method for Specific Charge in Deep Mining considering Influence of In Situ Stress

Table 4

Drilling quantity comparison at Hongtoushan Copper Mine.

Blasting zone	Original parameters		Test scheme		Percentage reduction of no. of blast holes (%)	Percentage reduction of length of blast holes (%)
	No. of blast holes	Length of blast holes (m)	No. of blast holes	Length of blast holes (m)
I	202	1655.6	161	1323.2	20.3	20.1
II	254	1960.4	210	1635.4	17.3	16.6
III	170	1527.4	146	1320.9	14.1	13.5
IV	311	2558	255	2111	18.0	17.5
V	254	2246.9	193	1736.9	24.0	22.7
Total	1191	9948.3	965	8127.5	19.0	18.3