Historic structures may require specialized vibration limits. Let GeoSonics/Vibra-Tech develop vibration criteria unique to your project.
The purpose of the project was to renovate the historic St. Elizabeths building to serve as the headquarters and Secretary’s Office of the Department of Homeland Security. The St. Elizabeths West Campus Center Building was constructed between 1853 and 1884 and housed the first federally operated psychiatric hospital in the U.S. It is listed on the U.S. National Register of Historic Places and is a U.S. National Historic Landmark. Demolition of the entire interior of the structure and its roof, repair and support of the foundation, and stabilization and restoration of the original brick façade was needed. The project specifications required that various types of monitoring be conducted for the protection of the masonry walls, including vibration monitoring. GeoSonics/Vibra-Tech was retained to determine if the project vibration limit was appropriate for the protection of the façade and, if merited, establish a new vibration limit. Wall deflection calculations and the behavior of the unreinforced masonry walls were defined and based on this information; a new vibration limit was established by GeoSonics/Vibra-Tech for the protection of the masonry façade walls. During the project, GeoSonics/Vibra-Tech installed 33 vibration monitors and performed the vibration monitoring at various locations and elevations on the masonry walls. The system alerted the necessary project personnel when vibration levels approached or exceeded the vibration limits established in the project specifications.