The $435-million, 1.2-million-sq-ft U.S. Coast Guard Headquarters project is the first phase of the Dept. of Homeland Security's planned consolidation and relocation effort in southeast Washington, D.C.
Clark Concrete poured 218,000 cu yd of concrete and placed 15,000 tons of reinforcing steel. Eleven different tower cranes were required during the 18-month construction schedule. On average, Clark poured nearly 3,500 cu yd of concrete per week for 42 consecutive weeks.
The largest single pour required 2,800 cu yd of concrete for an 8-ft-thick mat foundation. This pour took continuous deliveries of concrete supplied to an articulating-arm pump truck for 14 hours.
The site has a 145-ft elevation change, and Clark Concrete was required to construct nearly 12 miles of foundation walls. In all, Clark Concrete placed 523,000 sq ft of mat foundations terracing across seven different levels of the headquarters building.
In addition to the cast-in-place concrete superstructure, Clark Concrete was responsible for placing 10,000 cu yd of concrete for various site structures, including a man-made lake created by 18-ft-tall concrete retaining walls.
U.S. Coast Guard Headquarters Cast-in-Place Concrete Washington, D.C. Key Players
General Contractor: Clark Concrete Contractors, Washington, D.C.
Owner: General Services Administration, Washington, D.C.
Lead Design: WDG Architecture, Washington, D.C.
Structural Engineer: Cagley & Associates, Rockville, Md.
Civil Engineer: Loiderman Soltesz Associates, Rockville, Md.
Submitted by Clark Construction Group