The winning project of the Precast/Prestressed Institute’s 2019 Building Awards – Custom Solution entailed a unique setting on the western edge of Lake Michigan in Evanston, Ill. Chicago architect Perkins + Will was faced with the challenge of keeping the foundation of the new Ryan Fieldhouse & Walter Athletics Center at Northwestern University from being damaged by waves and ice rubble. The solution: a design-build precast concrete coastal wall made up of 109 5-ft. wide segments of varying heights and tapers arranged in two planes to replicate the appearance of a wave.
With the lakefront location, tight project sequence, and regulations that limit construction activities adjacent to the lake, precast concrete was the ideal solution, notes Tom Heraty, vice president of Sales and Engineering for the project’s concrete producer, Utility Concrete Products (UCP). The project’s design mirrors the naturally curved layout of the beach, with a rolled face and varying elevations in height. To protect the structure against the crashing waves and freeze-thaw environment, precise placement of epoxy reinforcement, embedded stainless steel angles, and hot-dipped galvanized/epoxy connectors was critical.
To ensure durability and a consistent surface, the architect required no mechanical connections or lifting points in the lakeside exposure wall. Morris, Ill.-based UCP addressed this challenge by using hidden splice sleeves on the beach-side erection. The sleeve is grouted through polyvinyl chloride ports that extend from the sleeve to the exterior face of the precast concrete wall.
Fabrication of the precast wall segments occurred off site and deliveries only took place when segments were ready to be installed. “The constraints associated with typical cast-in-place construction were alleviated, which allowed for an increase in site access and productivity,” says Patrick Brawley of Chicago-based SmithGroup JJR, the engineer of record.
Brawley adds that the wall is more than just a practical structure for the Northwestern campus. “The owners and community will see an acid-etched, integrally colored, extremely functional sculpture along the lakefront that artfully connects the beach and dune environment.”
PHOTOS: Utility Concrete Products