GNCB Presents at 20th Annual CSCE Geotechnical Seminar

GNCB was honored to present at the 20th Annual Connecticut Society of Civil Engineers (CSCE) Geotechnical Seminar on the Geotechnical Aspects of Infrastructure . David Freed, P.E., (Geotechnical Associate), and Amy Jagaczewski (Engineer), presented on the Adaptive Reuse of Holdredge Garage in Watch Hill, Westerly, RI. The project was recognized by this year’s CSCE’s Achievement in Civil Engineering Awards in the Structural Engineering and Sustainability categories.

Mr. Freed and Ms. Jagaczewski’s presentation highlighted the integration of all three GNCB services, Structural engineering, Geotechnical engineering, and Historic Preservation, in the adaptive reuse of existing historic infrastructure. The presentation and subsequent question-and-answer period addressed the following topics:

1.What were the subsurface conditions at the Holdredge Garage site which led to the selection of a helical pile foundation?

• Boulders in fill
• High groundwater
• Presence of tidal deposits (mixture of sand and organic soils)
• Presence of a suitable granular bearing material for the helical piles
• Need to install new foundations with minimum headroom to minimize the height at which the complex needed to be lifted. The construction site was constrained on all four sides by the presence of two buildings, a road, and an active parking lot.

2.What significant upgrades were made to the Holdredge Garage in order to stabilize the structure and meet current building codes? How did these upgrades conform to the Secretary of the Interior’s Standards for the Treatment of Historic Properties ?

• Selection of a helical pile foundation allowed minimal disruption to the existing complex while providing an opportunity to construct a new reinforced concrete foundation system.
• Major improvements to the complex’s flood resistance were made including elevating the structure a net of 2 feet and installing dry-proofing measures such as flood vents and break-away window.
• Structural reinforcing to support modern Code-Level gravity loads and lateral loads is obvious to allow differentiation from original materials. Minimal historic fabric was removed to install new structure.

3.What aspects of the Holdredge Garage Adaptive Reuse Project make it an example of sustainable infrastructure?

• Major improvements to public safety and aesthetics were made to a prominent, dilapidated structure at the entrance to the Watch Hill Historic District.
• Minimal removal or replacement of existing soils was made.
• The complex provides Watch Hill with 21,000 square feet of reclaimed rentable space.
• Existing parking behind the complex was not disrupted during construction nor reduced by the completed project.

Architect: NewPort Architecture, LLC

Contractor: Pariseault Builders

Learn more about this project: CSCE Honors Holdredge Garage at 2017 ACE Awards