CIVIL ENGINEERING FORMULAS

204 CHAPTER EIGHT

Vibration Control in Blasting*

Vibrations caused by blasting are propagated with a velocity V, ft/s; frequency
f, Hz; and wavelength L, ft, related by

(8.69)

Velocityv, in/s, of the particles disturbed by the vibrations depends on the
amplitude of the vibrations A, in

(8.70)

If the velocity v 1 at a distance D 1 from the explosion is known, the velocity v 2 at
a distance D 2 from the explosion may be estimated from

v 2 v (^1)  (8.71)

D 1

D 2 

1.5

v 2

 fA

L

V

f

Surface detonation Mudseam

Long free face

Inadequate stemming

of mudseam

FIGURE 8.3 Three causes of air blast. (Hemphill-Blasting

operations, McGraw-Hill.)

*Merritt—Standard Handbook of Civil Engineering, McGraw-Hill.