Footing reinforcing requirements Question - ACI 318-77
Footing reinforcing requirements Question - ACI 318-77
(OP)
Hi
I am looking at an existing building wanting to add a floor. But it appears to me that there is not enough steel in the footings. Basically, the building was designed to accomodate an additional floor. I am even under the stated allowable additional column load. But I decided to check things out anyway. When I check the footings using ACI 318-99 and FBC2001 requirements, I find that I don't ahve enough flexural reinforcing in the footings for the DL + LL load case. It looks like the original designer did not factor the loads when he checked the reinforcing.
The design was done to ACI 318-77 and and SBC 1982 ed.
Does anyone know if the loads needed to be factored back then for footing design? I don't have these codes and have not been in this business for that long too remember myself.
If so, what were teh live/dead factors?
Also, was live load reduction allowed for footings back then?
Thanks much in advance.
I am looking at an existing building wanting to add a floor. But it appears to me that there is not enough steel in the footings. Basically, the building was designed to accomodate an additional floor. I am even under the stated allowable additional column load. But I decided to check things out anyway. When I check the footings using ACI 318-99 and FBC2001 requirements, I find that I don't ahve enough flexural reinforcing in the footings for the DL + LL load case. It looks like the original designer did not factor the loads when he checked the reinforcing.
The design was done to ACI 318-77 and and SBC 1982 ed.
Does anyone know if the loads needed to be factored back then for footing design? I don't have these codes and have not been in this business for that long too remember myself.
If so, what were teh live/dead factors?
Also, was live load reduction allowed for footings back then?
Thanks much in advance.






RE: Footing reinforcing requirements Question - ACI 318-77
RE: Footing reinforcing requirements Question - ACI 318-77
It may be the original design was done using the Working Sress Method, in which case a completely different set of design values must of been used. Also live load reduction formulas may of been used per the local Building Codes not per ACI. Make sure you have the CORRECT Soil Bearing Pressure/Capacity. Good Luck.