Challenge
The Gulf Oil facility in New Haven needed to replace some old wooden dolphins used to moor their barges when transferring oil.
Solution
GZA GeoEnvironmental, Inc. (GZA) provided consulting engineering services required to evaluate and develop a full redesign for two of the existing mooring dolphins at the Gulf Marine Terminal in New Haven, Connecticut. GZA performed a limited topographic survey using GIS technology and a digital GPS device and conducted a facility evaluation. GZA reviewed available data with respect to existing structures and subsurface conditions and developed a generalized subsurface profile for use in pile evaluations at each of the existing dolphins.
GZA established design mooring loads to be used in the evaluation of the existing dolphins and for the design of new dolphins. The study was performed using the mooring analysis software Optimoor©. The design mooring loads were compared with the calculated structural and geotechnical capacities of the existing dolphins. It was determined that replacing the existing dolphins with more robust dolphins utilizing pipe piles and a reinforced concrete mooring platform would be the best option.
GZA modelled each new dolphin and performed pile group analyses using the software GROUP. A series of analyses were run, applying varying horizontal loads at different angles to evaluate the maximum tension that each dolphin could theoretically support. To resist tension in the dolphin piles due to the anticipated mooring loads, rock anchors were designed for the new dolphins.
GZA also assisted in the permit process and produced bid and construction documents for the new mooring dolphins. GZA also provided services during the bid and construction phases of the project.
Benefit
The safety and efficiency of the mooring system at the New Haven facility was improved.
