ACECO was contracted to perform the design and installation of the structural support, demolition of the foundation wall, interior demolition, and excavation, all while protecting the historic facade above. To support the existing building wall and facade, a detailed steel support system was installed utilizing the existing interior building columns as the main load bearing elements. Beams, tube steel, needle beams, diagonal braces, and knife plates were installed to support the building wall and exterior facade. This complex support allowed the foundation wall to be demolished under strict vibration and movement thresholds, creating the illusion of a “floating” building until the new addition is constructed, while meeting the aggressive project schedule.
