Tuesday, November 22, 2011


We use the 0.6 for the footing and soil overburden weight.  I always assumed the 0.6 was acting a "safety factor".  I sat through a ASCE webinar a few years back where the presenter used a 0.6 factor for the building structure and associated loads and 1.0 for the footing and soil overburden.  I'll try track down my notes for that presentation.

On 11/21/2011 5:26 PM, William Haynes wrote:
I wanted to see how many are using 0.6xFTG Self Weight of the footing when checking uplift due to wind or using the entire footing weight, 1.0xFTG Self Weight to help resist uplift. There appears to be several engineers that use 0.6x(everything else dead load except the footing) + 1.0x(FTG Self Weight) to check versus 1.0xGross wind uplift. The concrete has no allowance to be lighter than what you assume, and the footings have to be consistently dug to at least the dimensions you specify on your drawings. Is there anyone involved in forensics of metal buildings that have seen the footings uplift out of the ground when the code prescribed 0.6 wasn't factored on the footing self weight?

Will Haynes

Drew Morris, PE | Project Engineer

510 L Street, Suite 200 | Anchorage, Alaska 99501
Ph: (907)274-2236 | Fax: (907)274-2520 | Web: www.bbfm.com