Page 271 - Civil Engineering Formulas

SOIL AND EARTHWORK FORMULAS 205

2
The acceleration a, in/s , of the particles is given by
2 2
a 4
f A (8.72)
For a charge exploded on the ground surface, the overpressure P, psi, may be
computed from
W 1 3 1.407
P 226.62 (8.73)
D
where W maximum weight of explosives, lb per delay
D distance, ft, from explosion to exposure
The sound pressure level, decibels, may be computed from
P 28 0.084
dB 6.95 10 (8.74)

For vibration control, blasting should be controlled with the scaled-distance
formula:
D β
v H W (8.75)

where constant (varies for each site)
H constant (varies for each site)
Distance to exposure, ft, divided by the square root of maximum pounds per
delay is known as scaled distance.