1 Madison Avenue Project

Sometimes the biggest concern isn’t the building being worked on, but instead it’s the neighboring buildings or subway tunnels below ground. Let GeoSonics/Vibra-Tech monitor your project – allowing project personnel to have peace of mind during demolition and construction activity.

In New York City, demolition and construction activities were planned for 1 Madison Avenue, a 1.398 million square foot redevelopment site located in Midtown Manhattan directly adjacent to Madison Square Park. The project combined the redevelopment/reuse of the existing mid‐century masonry podium and the construction of a new tower. Levels 10 through 16 needed to be deconstructed, a total renovation was needed of the podium floors and a new core would be built along with a new 18 story tower above the 10th floor. Located in close proximity to the project site was the landmarked 5 Madison Clock Tower, currently functioning as the Marriott Edition Hotel, and a New York City Transit Authority (Transit) subway tunnel.

GeoSonics/Vibra-Tech was retained to conduct a pre‐construction inspection of 1 Madison as well as the surrounding buildings and any sensitive or historical structures like the clock tower at 5 Madison. Additionally, the transit tunnel adjacent to the site was inspected for the purpose of documenting existing conditions. A site‐specific vibration monitoring location plan was developed for the 5 Madison Clock Tower. GeoSonics/Vibra-Tech reviewed recent structural assessments of the building, the pre-construction inspection reports, site geotechnical reports, as well as means and methods of demolition, excavation and construction to determine the best placement for seismographs. Eighteen vibration monitoring stations were set up to monitor vibrations during the demolition and construction activities. In addition, acrylic crack gauges were installed to measure any movement during construction activities. An optical survey of 5 Madison and 1 Madison was also performed to monitor horizontal and vertical movement. Nine vibration sensors were also installed on the walls of the Transit subway tunnel. If vibration or movement approached set limits, project personnel were notified.

Check out our Inspection Services for more information on Pre-Construction Inspections.

Contact the New Jersey Office to learn more about this project.