International Spy Museum
Featuring the foremost collection of spy artifacts in the world, the International Spy Museum (SPY) is the only public museum in the U.S. solely dedicated to the tradecraft, history, and contemporary role of espionage and intelligence. The museum, opened in 2002, relocated eight blocks south to L’Enfant Plaza in 2018 to a $50 million building that transformed SPY, the neighborhood, and the Southwest Ecodistrict.
The Malrite Company and The JBG Companies collaborated on plans for the new 140,000 sf facility, which is located directly in front of the glass atrium on the Plaza. The construction increased the column loads on the Plaza by up to 2,800 kip (one kip equals 1,000 pounds-force), which necessitated retrofitting the existing foundation. Schnabel Engineering DC (SEDC)* was hired by JBG to work with the structural engineer, SK&A, on the retrofit and provided construction observation services.
To increase vertical load capacity, we recommended installing a group of micropiles through the existing footings. The solution was then fine-tuned by comparing 7-inch and 9.625-inch outside diameter micropiles. Each had advantages: better constructability with the smaller one and increased capacity with the larger one. Based on our findings and team discussions, we specified a hollow-core bar system consisting of a 7.87-inch diameter cross bit, T76S DYWIDAG hollow bar with 8.625-inch steel casing for the final design. A total of 70 micropiles with a design load of 200 kip compression and 140 kip tension were constructed in nine column locations.
*SEDC is an affiliate of Schnabel Engineering, Inc.
Photo: © Kevin Weber