Minimum Pile Length
Minimum Pile Length
(OP)
Does anyone have a good reference for minimum pile lengths for HP steel piles driven to refusal on limestone bedrock? The piles are only loaded axially. For PADOT, the minimum allowable pile length is 10 feet. I have used 6 feet in the past with success but that was based on my "gut" instinct and not "hard" science. I am looking for a reference that will explain why there is a minimum pile length. I am assuming it is based on pile driving stresses or lateral loading but am not sure.
Thanks
Thanks





RE: Minimum Pile Length
For end bearing, the socket length should be at least 2 to 3 times the pile diameter. I think both the conclusions are based on field tests.
Rgds
RE: Minimum Pile Length
RE: Minimum Pile Length
RE: Minimum Pile Length
RE: Minimum Pile Length
Rgds
RE: Minimum Pile Length
I would not be surprised if the minimum pile length was based on economics in comparing the cost of additional driven pile length versus extra excavation, concrete, and backfill required to build a spread footing at a deeper elevation. Maybe someone calculated that a footing with 10 feet maximum of extra depth would be cheaper than driving piles for a shallower footing.
RE: Minimum Pile Length
RE: Minimum Pile Length
I guess great minds think alike. We responded within 11 seconds of each other with essentially the same answer.
RE: Minimum Pile Length
RE: Minimum Pile Length
Yes, it all depends upon the minimum cost, the availability of equipment and the experience of the local engineers amongst other factors.