Ruchadaphon
Civil/Environmental
- Feb 7, 2024
- 2
Why is my designed rebar percentage suddenly becoming overstressed in story 9, the 2B and 3B columns have a very close amount of bending moment compared to the base level column of 2B and 3B.
I have obtained several results resembling this, when there are a huge amount of bending moments at the top of the building and designed rebar percentage at around 4% then reduced to 1% at the following stories, and suddenly it became O/S (overstress)(mostly because of P-delta exceed 1.4).
Additional Information
-ACI318-19 standard
-Spacing between columns is 7 m
-Story height is 4.2 m
-Column's concrete strength: 50MPa, 2B and 3B columns size is 400x1200 mm, 11B and 4B column size is 400x400 mm.
-Slab's concrete strength: 28 MPa, slab thickness is 350 mm.
-Non-sway
-No Lateral load, just compression
-Load combination, 1.2D+1.6L+0.5Lroof, 1.4D, and envelop.
I have obtained several results resembling this, when there are a huge amount of bending moments at the top of the building and designed rebar percentage at around 4% then reduced to 1% at the following stories, and suddenly it became O/S (overstress)(mostly because of P-delta exceed 1.4).
Additional Information
-ACI318-19 standard
-Spacing between columns is 7 m
-Story height is 4.2 m
-Column's concrete strength: 50MPa, 2B and 3B columns size is 400x1200 mm, 11B and 4B column size is 400x400 mm.
-Slab's concrete strength: 28 MPa, slab thickness is 350 mm.
-Non-sway
-No Lateral load, just compression
-Load combination, 1.2D+1.6L+0.5Lroof, 1.4D, and envelop.
