CDTA/Amtrak
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 1917 addition to the east. The existing 1840's portion of the structure was found to be supported upon dry laid stone with an estimated width of six feet, while the 1917 addition was found to be supported on a cast in place concrete foundation with an estimated width of ten feet. It was estimated by the Structural Engineer that bearing pressures on these existing foundations were on the order of about 4,000 to 6,000 pounds per square foot.
The project consisted of four story additions to the north and east of the existing building, as well as a two level parking garage set into the site grades to the east. The four story additions were supported on micro piles drilled and socketed into 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 challenges to the design and construction of the project. The project required excavations to locally extend up to about ten feet below the existing footings for an elevator addition and about 12 feet below grade in close proximity to Pine Street. As such, the project had strict requirements for lateral earth support and underpinning to protect the existing structure and adjacent roadways. Jet grout walls and underpinning techniques were employed to complete this work.
Cantilever jet grout walls with heights of up to 12 feet were used for lateral earth support along Pine Street, with individual elements extending about 12 feet below the excavation bottom. Jet grout underpinning elements, which were required for temporary and permanent support of the existing structure, extended to depths of up to 30 feet below grade adjacent to and beneath the existing foundations.
Dente Engineering completed the subsurface investigations, consisting of test borings and test pits, for the planned construction and provided recommendations for foundation and underpinning design. Foundation design analyses included establishing allowable axial and lateral capacities for micro piles as well as parameters for lateral earth support and underpinning design. Our Firm prepared contract drawings that outlined underpinning alternatives and design requirements for lateral earth support as well as specifications defining the performance requirements for earthwork control, micro pile installation and jet grouting. During the construction phase, Dente Engineering performed contractor submittal reviews and full time monitoring of all micro pile and underpinning activities for the Construction Manager. Our Firm also performed oversight of the pile load test and field testing of the jet grout wall and underpinning sections.
All Case Studies
Project Snapshot
- Name:
- CDTA/Amtrak
- Location:
- Albany, NY
- Completion Date:
- June 2002
- Services:
- Geotechnical Engineering and Consulting
- Underpinning and Excavation Services
- Support Consulting and Design