Low Cost Modernization of Berth 6, North Carolina State Ports

This paper discusses the replacement of a 40 year old general cargo berth at the North Carolina State Ports Authority in Wilmington, North Carolina. The main focus of the paper is on innovative techniques used by the designer, owner, and contractor to reduce the overall cost of the replacement structure. The final cost of the replacement structure was $43.33 per square foot. The replacement structure consists of an 18 inch thick reinforced two-way flat plate slab supported on both 20 inch square prestressed concrete piles and 18 inch diameter auger cast piles. The project involved the construction of approximately 12,400 square feet of new wharf and the replacement of approximately 145,500 square feet of existing wharf. The new wharf is capable of supporting 1,000 pounds per square foot and container handlers and replaces a wharf capable of supporting 350 pounds per square foot and HS 20 loading. Two different types of construction techniques are discussed; (1) Use of the exiting deck as a template for driving piles and as formwork for the new structure and (2) Use of the existing deck as a template for driving piles and then demolishing the deck and using the new piles to support traveling formwork.