Recommendations for Durable Anchor Pile Design in Floating Structures

Floating structures, including barges, pontoons, docks, wave attenuators, and ferry landings, are commonly held in place laterally through use of anchor piles embedded into underlying soils. These anchor piles and their connections to the floating structures present unique design challenges and are unforgiving if designed or installed incorrectly. Furthermore, there is limited guidance publicly available for design of these specialized elements. Projects evaluated include NYC Harbor ferry landing barges, concrete wave attenuators, and aluminum docks secured with individual steel pipe piles, as well as the large-scale Battery Park City floating ferry terminal and trussed jacket anchoring system. Consistent themes explored through the case studies are the need to define and liberally accommodate expected movements as well as address steel pipe pile and connection fatigue. This paper discusses best practices and recommendations for floating structure anchor pile design. The best practices and their importance will be demonstrated through successful case studies as well as evaluation of instances of premature failure.