Workshops: Rainier Square: Game Changer!

Ron Klemencic
Chairman, CEO
Magnusson Klemencic Associates, Seattle

The Rainier Square development in Seattle includes a 130,064-square-meter, 58-story, 259-meter tall mixed-use tower as the centerpiece. Bracing this tower against wind and seismic demands is a new structural system: a Concrete-Filled, Composite Plate Shear Wall (CF-CPSW) system, or as dubbed by AISC, Speed Core.

The innovative project is a composite steel frame with a shear-wall core and features a lateral system utilizing a sandwich of steel-plate walls tied together with steel rods and field-filled with concrete. Unlike a traditional concrete core, there is no rebar, no formwork of any kind, and no steel embeds required for steel gravity framing. Steel shear connection plates are simply welded to the steel sandwich panels. Perhaps one of the most significant aspects of this new core system is the time saved during the erection process since there is no waiting for the concrete to cure and formwork to be repositioned. The schedule for buildings designed with traditional reinforced-concrete core-wall systems has consistently been dictated by the cycle time of the concrete core construction.

The contractor’s evaluation of the system as compared to a traditional reinforced concrete core revealed a time savings of eight months, out of a total of 30 months, which will truly be a game changer. Developed by MKA in collaboration with Purdue University and The University at Buffalo with support from the Charles Pankow Foundation and AISC, Speed Core is ready for implementation across the country.