Memorandum

Steel casing for cast-in-place piling should be designated by nominal size, not inside diameter. Both ASTM A53 and A252 pipe is purchased by nominal size (outside diameter) and wall thickness. These are the commonly supplied pipe specifications. An example detail is attached for your information.

This practice shall apply to 24 inch and smaller pile casings. For specific pipe dimensions, see ASTM A53 or A252. Our specifications require that the steel casing thickness be determined by the contractor. If a minimum thickness is required for pile design, the detail should say "The pile thickness shown is the minimum thickness required to meet structural design requirements. The contractor shall determine the pile casing thickness required for driving and increase minimum thickness specified as necessary."

CCR:lr

JVL/NSB

Attachment

cc:     J. A. Weigel, Construction - MS47354

         F. Higgins, Bridge and Structures - MS47340