Design of Wood-Over-Concrete Podium Structures

Podium structures have become common in the United States as the demand has increased for dense, mixed use spaces and multi-unit residences. These structures are often designed as wood frame superstructures over concrete podiums, combining the economy and sustainability of wood construction with the height advantage and fire resistance provided by concrete. Using the maximum allowable building heights can result in structures as tall as five-stories of wood over two-stories of concrete. There are a number of unique design considerations for podium structures of this height. For wood superstructures, this includes large gravity and lateral loads resulting in designs that vary significantly from that of more traditional low-rise wood frame structures, as well as fire-retardant treatment requirements that must be met. The concrete podium level must be designed to support the wood superstructure, including large anchorage forces from the ends of the wood shear walls while maintaining a thin profile so as not to exceed overall building height limits. This webinar addresses these unique design considerations, particularly as they relate to the seismic design of five-story wood structures over post-tensioned concrete slabs.