Environmental Engineering Reference
In-Depth Information
D
P of air
shock wave fronts and the reaction time (t). Because the calculation is much
complex, it is obtained using empirical formulations of experiments.
The speci
c impulse (i) is directly determined by the super pressure
i ¼ A
W
2
=
3
R
¼ A
W
1
=
3
ð
R
[
12r
Þ
ð
2
:
88
Þ
R
i ¼ B
W
2
=
3
R
2
¼ B
W
1
=
3
R
2
ð
R
12r
Þ
ð
2
:
89
Þ
c impulse i is kgs/m
2
. For
the explosion of TNT in unlimited space, A = 40, and B = 25. For all other
explosives, A and B need calibration.
Here, r is the radius of an explosive; the unit of speci
r
Q
vi
Q
vTNT
i ¼ A
W
2
=
3
R
ð
2
:
90
Þ
Here, W is the mass of an explosive; R is the distance to explosion center; Q
Vi
is
the detonation heat of explosive i; and Q
vTNT
is the detonation heat of TNT.
2.4.1.3 The Damage of Air Shock Wave for the Target in the Explosion
of Liquid Explosives in Free Space
The shock waves, which are produced from explosion of liquid explosives in free
space, damage and fracture the surrounding targets (for example, building, equip-
ment, and human) in certain degrees. But the damage and fracture of various targets
from the shock waves of explosives are a very complex process. It is related with
not only the impact of shock waves, but also the shape, rigidity,
flexibility of the
targets. The loads and damage of buildings from shock waves are determined by
below factors.
fl
(1)
the super pressure
D
P of shock wave fronts
(2)
the action time of shock wave and the pressure change
(3)
the positions of buildings (the relative relation of buildings and shock wave
fronts, e.g., the fronts of shock wave are parallel or perpendicular with the
buildings)
(4)
the sizes and
figurations of buildings
(5)
the vibration periods of the buildings
The work capacity of explosives determines damage of explosion. They are
different following the change of explosive, packed mass, the surrounding media.
And the damage is also different if the distance to the explosion center varies.
