Math CentralQuandaries & Queries


Question from Sean:

Need to fill a 18" OD x 60 feet steel pipe pile with a wall thickness of 1/2" What is the amount of concrete I need in order to fill?
Thank you


1. Find the inside radius: 18"/2 - 1/2" = 8.5"
2. Find the volume of the pipe: (V = pi r2 h) 3.1416 x 8.5" x 8.5" x 60 ft = 13618.836 ft x in2
3. Convert to cubic yards: 13618.836 ft x in2 x 1 yd/3 ft x (1 yd/36 in)2

Final answer: 3.5 yards of concrete.

Stephen La Rocque.>

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