NEGATIVE SKIN FRICTION FOR PILES

[Mahmoud Fouad]

Would you please tell me wether the negative skin friction affects the design of pile cap or raft as a drag force - extra load on pile- affecting the moment and shear on pile cap or we just subtract it's value from pile capacity to check if it's capacity is adequate or not.
Want to know your opinions ?
Thank you in advance

 

[NJmike PE]

Skin friction is always a drag.