In urban cities and densely built areas, such as New York City, new construction may cause damage to existing nearby buildings. The damage from adjacent construction is typically caused by vibrations from demolition and construction activities, excavation, underpinning, pile installation, dewatering, foundation installation and fallen debris.
Preventing or minimizing damage to existing buildings from adjacent constructions requires that both design professionals and contractors pay careful attention to the existing nearby buildings. Preconstruction surveys, test pits and probes, soil investigations, and review of existing building records are among the important measures taken prior to commencement of adjacent construction. Thoughtful planning of the new building, careful execution of the plans, and proper inspection are needed to minimize damage to the existing buildings. Finally, it is very important to monitor the existing buildings for vibration and movement.
Chapter 33 of the New York City (NYC) Building Code, which is based on International Building Code, provides requirements for protection of the existing buildings. Furthermore, Technical Policy and Procedure Notice # 10/88 of the NYC Department of Buildings provides requirements for protection of the historic buildings.
This presentation will explain the authors’ studies prior to and during construction of two high rise buildings in New York City, which included preconstruction surveys, monitoring of the adjacent buildings with different structures and foundations, review of the foundation and support of excavation drawings for the new buildings, and reinforcement of the adjacent buildings.