Project Profile

U.S. Capitol Building Mechanical Renovation
Architect of the Capitol
Washington, DC

FEA provided instrumentation services to monitor potential structural movements of walls and floors during a major mechanical renovation project. The project consisted of lowering the basement level floor within sections of the House and Senate wings of the U.S. Capitol Building. Excavations ranged from four feet to 20 feet in trench areas. Load bearing masonry walls were underpinned and a limited amount of tunneling beneath existing room and corridor slabs was performed. To facilitate access to the mechanical rooms, access openings were cut into the existing terrace slab directly over the mechanical spaces, on both the north and south sides. FEA's instrumentation allowed engineers to monitor for potential movement of the walls and floor/terrace slabs above the mechanical rooms during construction.

FEA engineers designed and installed an array of horizontal and vertical tilt sensors, and crack transducers in an automated system that could be monitored remotely from our office. Hourly data samplings were posted on our website for client review. Predetermined threshold values allowed FEA to alert the contractor and owner of movement trends during excavation, construction, and equipment installation operations.

Scope Items:

Design and install an array of instruments to allow detection of movement or settlement of structural walls, beams, slabs, and crack growth
Automated remote data collection at FEA office
Real time data sampling and posting to website for easy access and review by FEA engineers and the client
Predetermined thresholds for settlement and crack growth allowing immediate contingency response by contractor to site conditions

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