In this project the piles are subjected to lateral loads, this generates moments at the upper end up to about 6 meter below the ground surface. Also in this project the subsurface layers contains Sabkha soil (very loose soil) so it is required the reinforcement to continue up to the lower end of...
It was difficult for me to find this info. I found and attaching it.
From ACI 336.3R-93
4.2.2-- The clear spacing between vertical reinforcing
bars should be at least 3 times (preferrably 5 times) the
size of the maximum coarse aggregate or 3 times the bar
diameter whichever is larger.
4.2.3--...
