- Project funded in part with a federal grant
- Evaluated existing conditions and the ability to accommodate deeper draft and heavier deck loadings
- Performed subsurface exploration program to advise design of future improvements
- Pier rehabilitation included accommodation for heavier deck loads and deeper berth drafts
- Prepared construction documents for repairs to the east and south faces of the cellular cofferdam pier
- Provided bid and construction phase support services for sheet pile replacement of the east and south faces of the pier
- Provided geotechnical design guidance for pile supported deck extension on the pier’s east face
- Construction phased to maintain operations during construction
Quonset Development Corporation (QDC) manages and operates the Quonset Business Park, including its two WWII era piers. The facility is a major auto import facility and is looking to provide support for the offshore wind industry in New England.
Challenge
Following the discovery of deficiencies in the cellular cofferdams that define Pier No. 2, and with a desire to increase the berth depth and deck load capacity of the existing structure, improvements were required at the pier.
Solution
GZA was engaged by QDC to perform an emergency evaluation of existing conditions. GZA evaluated pier loading, estimated cofferdam interlock tensions, developed allowable interlock stresses and consulted with QDC regarding pier load restrictions. GZA initially designed and detailed a load transfer platform to provide a local increase in allowable pier live load, thereby allowing for the off-loading of heavy offshore wind equipment at designated areas of the pier. GZA completed a subsurface exploration program consisting of test pits and land and water-based test borings to supplement existing subsurface data. GZA prepared a Geotechnical Data Report (GDR) that was included in RFPs and Construction Document packages associated with the design and construction of a new bulkhead, pier extension, heavy lift platform, and fender system. GZA also completed a drivability study to evaluate pile installation conditions for each of the proposed improvements. Phase 1: GZA was subsequently awarded the first phase of a three-phase program to rehabilitate the pier and extend the east face to add another berth. This phase included the design of a new sheet pile wall and support services during construction. Phase 2: GZA provided geotechnical consultant services during the second phase for a pile supported pier extension. Phase 3: GZA designed and provided construction-phase services for new sheeting on the southern face of the pier.
Benefit
The rehabilitated pier has two deep water berths to service the existing auto import industry and provide the heavy deck load capacity needed to support the offshore wind industry.