Large Diameter Fiber Reinforced Polymer Monopile Dolphin System Revisited

In 2014 the Virginia Department of Transportation (VDOT) implemented a project to replace failure-prone timber pile cluster dolphins at the Jamestown-Scotland Ferry (JSF) with a system better suited to resist impacts from increasingly larger ferry vessels. After an initial study, large diameter fiber reinforced polymer (FRP) monopiles were selected as replacement dolphins. While this application of large diameter FRP piles was largely unproven in practice, it was selected for its combination of strength, flexibility, resistance to corrosion, and low life-cycle cost. The initial JSF dolphin study was described to the 2016 PORTS conference in McCarty et al. (2016) A Case Study and Recommendation for Large Diameter FRP Monopile Dolphin Systems. This paper revisits the system after conclusion of two construction contracts to install the FRP dolphins. Pile driving difficulties and successes from both installation contracts are discussed. Engineers working on designs with large diameter FRP piles will benefit from the information provided.