Soaring 850 feet over downtown Seattle, the Rainier Square Tower is a sight to behold. The 58-story mixed- use behemoth turns a mirror on the city — literally — with its thousands of mirrored glass panels sloping up into the sky.

But it isn’t just aesthetically magnificent. The tower is best-known for its innovative new structural construction: a concrete-filled, composite plate shear wall system — also known as SpeedCore. The 2022 Paul Zia Distinguished Lecture on the design and construction of the Rainier Square Redevelopment Project highlighted the system’s ability to brace the tower against Seattle’s wind and seismic activity while also cutting the construction time to just 22 months.

Now in its 21st year, the Paul Zia Distinguished Lecture Series was established in 2002 to showcase some of the world’s most exciting and challenging projects and the engineers who work to make them happen. The lecture series honors Professor Emeritus Paul Zia, a former professor and department head of CCEE and a structural engineer who is eminent in research, professional society leadership and practice. For more than 50 years, he has been engaged in teaching, research and consulting in many areas of concrete materials, reinforced and prestressed concrete structures, and construction, advising more than 60 master’s and doctoral students.

“What’s really special about this lecture is that it not only honors Dr. Zia, but it is a wonderful opportunity to link students to the real world of engineering and give them a chance to see how what they learn at CCEE can translate to doing really big things,” said CCEE Department Head Jackie MacDonald Gibson. “It also introduces the public and the broader community to the great work that can come from civil, construction and environmental engineering. Dr. Zia is such an incredible example of how research in civil engineering can make people’s lives better. His work has led to safer structures for all of us.”

At this year’s lecture, Amit Varma, Karl H. Kettelhut Professor of Civil Engineering and director of the Bowen Lab for Large-Scale Civil Engineering Research at Purdue University, and Ron Klemencic, chairman and CEO of Magnusson Klemencic Associates, discussed how the use of SpeedCore and steel-concrete composite construction aided in the durability and accelerated the timeline of the project.

SpeedCore’s shear wall core system uses steel plates instead of traditional rebar and formwork between concrete elements, reducing the amount of time necessary to create the floors of the tower. According to the American Institute of Steel Construction (AISC), the steel in SpeedCore can support up to four floors of decking by itself, making it possible to erect four floors in a week.

The system, developed by Varma in collaboration with Magnusson Klemencic Associates, Purdue University and the University at Buffalo (The State University of New York), was originally estimated to shave about eight months off Rainier Square’s construction schedule in comparison to traditional methods. In actuality, it took just 22 months to deliver the project — 10 months ahead of the original schedule.

In addition to the composite steel plate core, outrigger and belt trusses were added about two-thirds of the way up the tower. The trusses act in the same way that ski poles help a skier: they add balance and stability to the building.

“It’s something that’s never been done before: A whole new structural system, a whole new way to assemble a building,” Klemencic said.