Hello,
I'm designing some equipment foundation by using Plant Foundation in STAAD Foundation Advanced. I wonder Load combination from ASCE7-05 which is provided by Load Combination Table. Should SWF and SBF be factored with the same value as other Dead Load ? Both of them either Service Load Combination or Ultimate Load Combination are not factored with the same value.Can you give me an explanation or any misunderstanding of my concept?
Phonlayuth Thongpasuk Phonlayuth Thongpasuk @Aswathi
SWF and SBF are different things. SWF (Self Weight Factor) is a factor that is used to include self-weight in load combination. Generally, it takes same factor of dead load except some specific clause at some specific code.
SBF is Safe Bearing capacity factor. In general, keep it one for all cases unless you have approval for increase from geotechnical department. This is used to increase the bearing capacity only for seismic and wind cases (generally 10-25% hike is allowed and only for sandy soil hike is allowed. For clay increase of bearing capacity is strictly prohibited. And any increase, needs to be vetted by a geotechnical expert.
thank you for explanation.