They're filling each drilled hole / pier / anchor / whatever the technical term is one by one as they are ready. This is also why the mobile crane is there and gone repeatedly.
Having watching the progress over the past weeks, the placement and diameter of these drilled holes certainly seems random or sporadic. I can't figure out any pattern that correlates to the building layout itself. If anyone has extra time and is bored, you could probably watch the time lapse day by day and mark each hole and its diameter... would also probably give us a better idea as to how many more they're goind to drill before they move onto the next phase of construction.













