The project consisted of additions and improvements to the New York State Court of Appeals located at the corners of Pine and Eagle Streets in the city of Albany, New York. The main portion of the existing structure was constructed in the 1840's with a large addition to the east in 1917. The existing 1840's portion of the structure was found to be supported upon dry laid stone with an estimated width of 6 feet, while the 1917 addition was found to be supported on a cast in place concrete foundation with an estimated width of 10 feet. It was estimated by the structural engineers that the bearing pressure on these existing foundations was on the order of about 4000 to 6000 lb/sq. ft.
The project consisted of four storey addition to the north and east of the existing building, as well as two level parking garage set into the site grades to the east. The four storey additions were supported on micro-piles drilled and socketed into the bedrock at depths of nearly 100 feet below grade, while the parking deck was supported on spread foundations.
Development of the site in an urban area and adjacent to an existing building presented some peculiar challenges for excavation. The project required excavations to locally extend up to about 10 feet below the existing footing for an elevator addition and about 12 feet below grade in close proximity to Pine Street.
Underpinning is preferred when placing a new foundation below the existing foundation or during strengthening of existing foundation. Due to the nature of this site and being in an urban area, the project had strict requirements for lateral earth support and underpinning