UnneutralAxis
Structural
- Apr 5, 2009
- 54
I posted this in the structural forum, but probably is better suited in here. This might not be an original idea and it might not be the best idea ever. Just wanted some opinions.
I have a site that got a pretty bad soils report and a rigid mat was recommended. Pretty light loads, one story office building. 100 psf floor load. Line loads less than 1200 plf. Point loads less than 20 kips. Seismic design category B. Will be using a mat 12" thick.
Frost depth is 30". Owner doesn't want to step down into the finished floor. I worry a little bit about doing a turn down as I don't want to have the possibility of an increased bearing pressure occurring at the turn down. Has anyone used a trench of 57s to get below the frost depth at the perimeter? Seems to be a descent idea, the only real concern I have is with scour. A rigid insulation detail would be provided just inside the trench interior of the building.
I have a site that got a pretty bad soils report and a rigid mat was recommended. Pretty light loads, one story office building. 100 psf floor load. Line loads less than 1200 plf. Point loads less than 20 kips. Seismic design category B. Will be using a mat 12" thick.
Frost depth is 30". Owner doesn't want to step down into the finished floor. I worry a little bit about doing a turn down as I don't want to have the possibility of an increased bearing pressure occurring at the turn down. Has anyone used a trench of 57s to get below the frost depth at the perimeter? Seems to be a descent idea, the only real concern I have is with scour. A rigid insulation detail would be provided just inside the trench interior of the building.
