Careful design and coordination minimized disruptions to the historically sensitive marble finishes. Mechanical upgrades required extensive structural design, including sub-grade trenching as well as floor and wall penetrations through historic materials and systems.
The United States Supreme Court building, unlike other buildings on Capitol Hill, had not been upgraded since its completion in 1935. Silman provided structural engineering services for its modernization; work included the upgrade and replacement of building systems. Some building functions were also relocated in order to use space more efficiently, improve service to the public, and comply with safety codes. The project consisted of two phases combining new construction with historically sensitive renovation while the building continued to remain occupied.
New construction during Phase I included a two-story underground annex adjacent to the existing building, providing necessary space for the Court Police and new mechanical equipment, and a new mezzanine framing level within the historic structure for high-density storage. A new underground parking facility requiring significant underpinning (30 feet down), monitoring, and blast resistant protective design was also incorporated into the scope of work. Silman also designed the foundation systems for expansion of the existing building.
Phase II involved modernization of the existing building’s five floors, including a reconfigured visitor’s entry and the removal of a column below the main hall.
To address security issues, Silman analyzed all existing windows for both blast and ballistic resistance. As a part of this analysis, Silman designed steel sub-frames to resist reactions from a blast force on the windows.