Cast-in-place Concrete Piles - Self Weight Included in Design
Cast-in-place Concrete Piles - Self Weight Included in Design
(OP)
This may sound like a stupid question, but hey, as they say, no such thing as a dumb question.....
Anyway,
Do I need to include the selfweight of the concrete pile in the design of the pile itself. I am designing on a basis of skin friction only.
Anyway,
Do I need to include the selfweight of the concrete pile in the design of the pile itself. I am designing on a basis of skin friction only.






RE: Cast-in-place Concrete Piles - Self Weight Included in Design
Cheers,
YS
B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...
RE: Cast-in-place Concrete Piles - Self Weight Included in Design
Does anyone know where I can find this in code/standards?
RE: Cast-in-place Concrete Piles - Self Weight Included in Design
RE: Cast-in-place Concrete Piles - Self Weight Included in Design
His reasoning was that you are removing ~125lbs/cu.ft of soil and replacing it with ~150lbs/cu.ft of concrete.
Because of this, you are looking at less than 20% net increase in loading, which one could argue is insignificant based on their large safety factors. They base their skin friction capacities on safety factors of 2.5 to 3.5
Does everyone agree with this? I am guessing mixed opinions.
RE: Cast-in-place Concrete Piles - Self Weight Included in Design
RE: Cast-in-place Concrete Piles - Self Weight Included in Design
RE: Cast-in-place Concrete Piles - Self Weight Included in Design
I recently had a geotech engineer go so far as to tell me I could ignore the self weight of 6 foot diameter drilled piers that were up to 90 feet deep. I couldn't quite bring myself to that.
RE: Cast-in-place Concrete Piles - Self Weight Included in Design
MJ Tomlinson states (Foundation Design and Construction, 6th Ed): "At the limit state . . . the ultimate bearing capacity of a pile is given by the equation "Qp = Qs + Qt - Wp" . . . Usually Wp is small in relation to QP and is is often neglected because it is not much greater than the weight of the displaced soil. However, it must be taken into account for marine piling where a considerable proportion of the pile length extends above the sea-bed." He goes on to talk about Eurocode 7 where they talk about design bearing capacity rather than the ultimate value.