COLUMN SIZE INCREASE 5

[WiQi]

Hi,

RC column of size 18"x18" column height 11' have to be increased to size 30"x30"

how can we do this? building is under construction just columns are constructed upto 11' height on a raft 24" , design revision says column should be increased. code followed UBC 97, seismic zone 3. two more stories will be raised on these columns.

Regards

 

[RHTPE]

WiQi, You might get better suggestions if you were to post at least a plan showing the structure around the column of concern.


Ralph
Structures Consulting
Northeast USA

 

[WiQi]

sure, here it goes, i had problem uploading to a free space.

 

[WiQi]

kindly check the link below to check columns sections

 

[KootK]

@WiQi: I'm not clear on the basement wall business. Is there a basement wall surrounding these columns that ties into the diaphragm at the top elevation of the columns? Technically, those would be shear walls and not basement walls. If that's actually the case then I would argue that the beam/column ratio doesn't apply. I don't see any walls in the drawings that you've posted however.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[WiQi]

@KootK: wall is there around the periphery in between columns but it is just at lower ground(basement) in upper two stories there is no wall between columns. this wall is not shear wall but basement wall which will retain the soil just.