MIL-HDBK-1004/10

9.10.2

a)

Total submerged area of bulkhead:

Area of PZ 27 piling is 2.96 ft per

lineal foot per foot of depth

Area in water = 2.96 x 36 x 1,000 = 106,560 ft

Area in mud (front) = 2.96 x 15 x 1000 = 44,400 ft

Area on shore side =

sheet piling:

2.96 x 56 x 1000 = 165,760 ft

tie backs:

1" diam x 3.14/144 in./ft x 24'

long x 100 = 365 ft

total = 165,760 + 365 = 166,125 ft

b)

Protective current required on front side:

in

water - 106,560 ft x 0.5 mA/ft = 53.28 A

in mud - 44,400 ft x 0.2 mA/ft = 8.88 A

total - 53.28 + 8.88 = 62.16 A

c)

Protective current required on shore side:

166,125 ft x 0.05 mA/ft = 8.3 A

d) Output from Type A420 Type III aluminum alloy anodes is 4.75 A

(refer to Table 24).

Number of anodes required for current output:

N

=

I/i

where

N

=

number of anodes required

I

=

current requirement (A)

i

=

output per anode (A)

N

=

62.16/4.75

N

=

13.08 (say 13)

e)

Minimum weight of anodes required for 15 year life:

W=

YSI

201

Integrated Publishing, Inc. |