Question

contractor will use a package emulsion having a specific gravity of 1.25 and relative bulk strength of 130 to open an excavation in diabase rock, specific gravity 2.76. the drilling equipment available will drill a 4-in. blasthole. the explosive comes packaged in 3-in-diameter sticks. what is the recommended burden distance for the first trail shot? round the calculated burden distance to the nearest foot.

Answer 1

Answer:

The burden distance is 7 ft

Solution:

As per the question:

Specific gravity of package emulsion, $SG_{E} = 1.25$

Specific gravity of diabase rock, $SG_{R} = 2.76$

Diameter of the packaged sticks, d = 3 in

Now,

To calculate the first trail shot burden distance, B:

$B = [\frac{2SG_{E}}{SG_{R}} + 1.5]\times d$

$B = [\frac{2\times 1.25}{2.76} + 1.5]\times 3 = 7.22$

B = 7 ft