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[Saurabh Raj]

Dear sefians,

Hope you are doing well,

Can we consider different length of pile in one pilecap if there is no chance for loading in another direction. In my case there is a retaining wall with eccentric loading. So, soil side load will be very less in compare to another side.

We are trying to optimize the quantity.

Please help. Your responses will be helpful.

Thanks.

[vikram.jeet]

Generally pile cap having piles with different  length not provided , unless rock encountered.
For Eccentricity , ,   match cg  due to loads and moments  with pile cg

It implies , that provide more piles beneath walls toe side ,  than on heel

[Saurabh Raj]

Vikram Sir,

Thanks for your response but we don't have much margin beneath the wall (At heel location). May I know that, is there any codel provision or any limitation not to providing different length of pile in one pilecap.

Thanks

[vikram.jeet]

Dear Er,,
Not able to understand yr str
Cannot say much

If it is ret wall loaded at stem  , you may be having load as well as moments,, see ecc e =M/P
Provide piles of same length matching cg

Even if ypou cannot match cg due to space,, take P & M on pile group  ,, piles will be subjected to different loads based on their positioning.
Your view is that those piles having lesser load to be of less length,,

Certainity of loads to exist is there,, but  moments, especially ep moments may /may not exist to the quantum we calculate,, and there fore ,,
Calculate  pile loads with moments including EP
Secondly calculate pile loads without EP

Provide higher of two  for each pile
If you feel there is substantial change in loads,, vary pile length, but proof consultant  must be informed.

See some specialist literature on net,, I think capacity of such vary pile length group is reduced , but check at net.

Best wishes

[spsvasan]