In 1780, Thomas Jefferson took on the design of the new Virginia State Capitol Building. Drawing on a mix of ancient vocabulary and modern construction techniques, he created a new style that was distinctively American and set the precedent for the nation’s public architecture. Through preservation engineering, Silman and the project team developed a unique approach that not only met the client’s future needs with master planning assistance but also providing structural engineering to assist with the renovation recommendations to minimize the impact on the historic landscape and protect this irreplaceable architectural resource. The master plan included 27 buildings and the surrounding landscapes on the historic campus with a comprehensive investigation.
Based on the project team’s recommendations for renovation, in 2004 the Commonwealth of Virginia undertook a $100 million historic renovation of the existing Capitol Building, and the construction of a new below-grade extension to accommodate visitors to the site, resulting in a renewed 100,000 sf facility. Using conventional structural systems to support the restored landscaping, integrated with unique and sophisticated foundation elements, the new underground extension was constructed directly against the historic south portico at a depth of up to 28 feet below the existing foundations. Protection of the historic structure was achieved through a unique design of the structure and foundation elements, coupled with real-time movement monitoring and design accommodation for an active response to settlement.
Preservation Engineering was used to assess the ability of the existing structure to accommodate increased loadings, and to address several areas where structural modifications to historic fabric were necessary. For example, the original Jeffersonian era vaults and load bearing wall construction required both a verification of capacity as well as innovative design and detailing to create new openings. With this landmark renovation, Jefferson’s ‘Temple on the Hill’ is well preserved for its third century of service with renewed life.