Here is sample layout with steel usage for library stackroom application.
lightweight concrete do come with finishing premium and is not preferred around our location. The example assumes normal weight concrete 3.5" on top of 3" composite deck flutes (total 6.5" slab thickness). This...
Usually, single pile at the corner/side is checked for punching through the cap.
Beside dimensional requirement, generally 1.5 times pile diameter is used for pile center to the outside edge of cap.
We usually provide Helical Anchors (micro pile as already suggested above)adjacent to the existing footing with the lifting brackets. Cost most probably depends on your locality. I have seen those costing about $1200.00 a piece. You may be looking at another $200.00-$300.00 for lifting brackets...
