I have to design a turndown slab. Slab on grade with thickened section at perimeter winding down to the thickness of the slab on a 45 degree angle. This is for a prefabricated metal building having a span of 40'. The rigid frames are spaced roughly 25' c/c. My concern is for the point load provided by the frame.
My idea is to design that section as a continuous multi-span beam, calculate it for punching shear and bending. For frost heave, I am planning to provide rigid vertical an wing insulation, as well as making sure that there is an adequate amount of structural fill under, and a layer of 4 mil polyethylene. Any suggestions if I am missing something ? Am I on the right track ? As much as possible I try to stick to the more traditional pier-footing foundation with a perimeter frost wall.
My idea is to design that section as a continuous multi-span beam, calculate it for punching shear and bending. For frost heave, I am planning to provide rigid vertical an wing insulation, as well as making sure that there is an adequate amount of structural fill under, and a layer of 4 mil polyethylene. Any suggestions if I am missing something ? Am I on the right track ? As much as possible I try to stick to the more traditional pier-footing foundation with a perimeter frost wall.
