Kayengineer
Structural
- Aug 23, 2023
- 1
Long time reader, first time posting.
I am demoing about 4’x4’x4’(deep), 3’ adjacent to a south wall, into an existing (approx 28’) below grade flat two-way concrete slab for a new mechanical device.
The Stru was built in early 60s, compressive strength is unknown, top of slab reinforcement is #8@12” OC (N-S) with #4@12” OC (E-W), it doesn’t appear there is any bottom reinforcement in that slab area after reviewing as-builts (which is concerning).
My questions are:
1. Should I check to see if the soil pressure below the slab would effect the new demo’s area? If so, how would you approach?
2. Add additional steel in the bottom portion of the demo’d slab since there appears not any?
3. Is there a concerned for shear of the main ‘beam’ reinforcement, 7#11 (E-W) @2-3” OC, left adjacent 5’ from the demo’d area?
I am demoing about 4’x4’x4’(deep), 3’ adjacent to a south wall, into an existing (approx 28’) below grade flat two-way concrete slab for a new mechanical device.
The Stru was built in early 60s, compressive strength is unknown, top of slab reinforcement is #8@12” OC (N-S) with #4@12” OC (E-W), it doesn’t appear there is any bottom reinforcement in that slab area after reviewing as-builts (which is concerning).
My questions are:
1. Should I check to see if the soil pressure below the slab would effect the new demo’s area? If so, how would you approach?
2. Add additional steel in the bottom portion of the demo’d slab since there appears not any?
3. Is there a concerned for shear of the main ‘beam’ reinforcement, 7#11 (E-W) @2-3” OC, left adjacent 5’ from the demo’d area?