Overstressed Columns

[laguns]

I have a 20 storey building with a three level basement supported on a piled raft (also modelled with springs). Zone 2A. I have used an overstrength factor of 2.8 as per code based on the category and classification of the residential building.

All my columns are overstressed, despite me previuosly extracting the loads from Etabs and into Prokon and designing them separately. Once I got a suitable size from Prokon (within the interaction diagram) i then changed the columns in Etabs one by one and entered the rebar and then re-analysed the model.

All columns are intermediate sway frame, typical column sizes are 500mm by 1000mm each carrying about 16msq floor area. The core walls are not overstressed. All showing 0.0025.

Im not sure what to do or what else to check to eliminate the overstress. Thanks.

 

[structech08]

Hi Laguns,

To send us your etabs model to verify.

Thanks,
structech08

 

[laguns]

Thanks,

ive sorted the problem out.