Environmental Engineering Reference
In-Depth Information
The volume of a standard cone is
3
p
r
W
/
W
3
V ¼
1
=
The relationship of a standard cone volume and the explosive mass
ˉ
is in
Eq.
2.45
.
x
¼ KV
a
KW
3
ð
2
:
45
Þ
The index K represents the required explosives for throwing unit volume of
media in the formation of standard blasting cone, or the uniconsumption of
explosives. K is related with the properties of the media, and the properties and
experiments with explosives.
The packing mass of explosives for power throwing blasting is calculated by
below equation.
x
¼ KW
3
f
ðÞ
While,
6n
3
f
ðÞ
¼
0
:
4
þ
0
:
In the evaluation of the explosives by casting cone method, the places of
explosion and the packing diameters are exactly the same. The variation of uni-
consumption displays the different work capability/ability of explosives. In the
same conditions, K
1
is for explosive 1 and K
2
is for explosive 2. The work ability of
two explosives is inversely proportional to their values, A
1
/A
2
= K
2
/K
1
. This
comparison should be conducted when the two values of n are very close to each
other. The repeatability of this method is poor. Packing with relatively large amount
of explosives is better.
All above three methods have their own disadvantage for measuring the work
ability of explosives. There are new experiment methods in study. For example,
when the explosion is under water, the new experiments include the broken dome
method of spray center initiate velocity or dome method of water cylinder, the
measurement of water impact energy, and bubble energy. For explosive cylinders
with certain diameter, it
s also a method to measure the velocity of radial dis-
placement of cylinder shell after the explosion from one end. The earthquake
method measures the highest pressure of shock waves in the water (sand, or earth),
which are certain distance away from the explosion center. The experiment data of
earthquake method match the calculated one very well. Because the experiment
earthquake energy is linearly proportional to the mass of packed explosives, it
'
'
s
suitable for measuring the work ability of explosives.
