Wall thickness of piles used under offshore platform should be designed to prevent local buckling. For piles that are to be installed by driving where sustained hard driving (820 blows per foot with the largest size hammer to be used) is anticipated, the minimum piling wall thickness used should not be less than:

Using metric sistem:

where t is the wall thickness and D is the diameter.

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Minimum wall thickness for normally used pile sizes should be as listed:

Pile diameter => Nominal Wall Thickness

610 mm (24 in.) => 13 mm

762 mm (30 in.) => 14 mm

914 mm (36 in.) => 16 mm

1067 mm (42 in.) => 17 mm

1219 mm (48 in.) => 19 mm

1524 mm (60 in.) => 22 mm

1829 mm (72 in.) => 25 mm

2134 mm (84 in.) => 28 mm

2438 mm (96 in.) => 31 mm

2743 mm (108 in.) => 34 mm

3048 mm (120 in.) => 37 mm

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As said in API code, the preceding requirement for a lessed D/t ratio when hard driving is expected may be relaxed when it can be shown by past experience or by detailed analysis that the pile will not be damaged during its installation.

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For any kind of questions on this article you can contact the author at:

ofs@hotmail.it

Eng. Onorio Francesco Salvatore