Port Manatee Berth 12 Wharf Extension and Container Yard

The Port Manatee Berth 12 Wharf Extension and Container Yard project involved the extension of the existing berth 12 in the Tampa Bay, including a 590-foot-long combination pipe/sheet pile bulkhead, fender system, cast-in-place concrete cap, asphalt paving, trench drain, mechanical dredging and rip-rap work. Additionally, this project involved the construction of a fully functional 10-acre upland container storage yard.

American Bridge completed major technical challenges throughout the project that included pile driving and the mechanical dredging. The bulkhead is a pipe-z combination wall composed of 64-foot-long by 30-inch diameter pipe piles and 56-foot-long AZ-18 steel sheet piles. The crane used to drive the wall was located on land and the wall was driven parallel to the shoreline in 20-foot-deep water. This presented technical obstacles in selecting the proper equipment that could safely perform the job as well as ensuring that the pipes were driven in the proper locations so sheet piles would fit when driven at a later time.

The mechanical dredging task was performed with a clamshell and utilized a similar arrangement to pile driving. The crane sat on land while dredging up to 65 feet perpendicular from the shoreline. The dredge material was hardened clay and the process was completed on time by having a high level of efficiency due to daily in-house hydrographic surveys. The crane operator had daily surveys that showed exactly what the seabed looked like. This eliminated the need to go back to previous dredged areas and rework them due to excessive high spots as well as limiting the amount of over dredging that can be costly.

A significant challenge with both activities was the early spring weather due to cold fronts moving through Florida at that time of year. The high winds and waves shut down these operations for a day or two every time they passed through because divers were needed to complete that work. The concrete encapsulation was challenging due to the large amount of time required to set concrete forms along a pipe-z combination wall. The rip rap slope was designed on a 3:1 slope 54-foot-wide and required the use of long reach equipment to excavate and place the stone. However, both types of construction were successfully completed many times on previous jobs by the highly skilled American Bridge crews.