Solution:

(1) For (Pso)max = 15 psi, W/V = 0.017 from Figure 14.

Therefore, V = 125/0.017 = 7,350 ft3

(2) For a cube, L = V1/3 = (7,350)1/3 = 19.4 ft

Therefore, length, height, and width of cubicle should be

19.4 feet

(3) For a given distance, R, of 200 feet, the scaled distance

R/W1/3 = 2001(125)1/3 = 40 ft/1b1/3

(4) From Figure 13, Pso = 1.0 psi behind the back wall,

1.5 psi behind the sidewalls and 1.8 psi out the open

front. (Pso)max = 15 psi, which is greater than all

the other pressures listed above. Therefore, the

pressures are correct.

c. Airblast from Underwater Explosions.

Problem:

Determine the overpressure at a position 10 feet above the

surface and 60 feet from Surface Zero (y = 10 and R = 60)

produced by 1,000 pounds of TNT detonated 25 feet below the

surface.

Given:

(1) Type and weight of explosive.

(2) Location of explosive.

Solution:

(1) Calculate the scaled charge depth, [lambda]d.

(2) Calculate the scaled horizontal distance, [lambda]x.

(3) Calculate the scaled vertical distance, [lambda]y.

(4) From the appropriate figure, read off the overpressure.

Include accuracy of +/- 30 percent.

Calculation:

Given:

(1) Charge weight, W = 1,000 lb of TNT.

(2) d = 25 ft, R = 60 ft, and y = 10 ft

Solution:

(1) [lambda]d = d/W1/3 = 25/1,0001/3 = 2.5 ft/lb1/3

(2) [lambda]x = R/W1/3 = 60/1,0001/3 = 6 ft/lb1/3

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