Specifies the way in which the slab is placed in the model with respect to the support plane. To change the options on the list, edit the Slab Face Position select list in Catalog.
Center
Indicates that the slab is placed with respect to its centroidal axis.
Top
Indicates that the slab is placed with respect to its top face.
Bottom
Indicates that the slab is placed with respect to its bottom face.