Steel Pipe Pile Design, Installation, and Dynamic Testing for a New Pier in Georgetown, SC

A new pier extension was constructed for the South Carolina State Ports Authority (SCSPA) at Pier 31C in Georgetown, South Carolina. This pier was founded on 28 steel open ended pipe (OEP) piles driven into the underlying limestone and silts of the Pee Dee Formation. To account for the expected high lateral loads the new pier may experience during ship impacts and movements, both vertical and batter piles were installed. To the authors’ knowledge, this is the first application of steel open ended pipe piles as a maritime foundation system in the Georgetown, South Carolina area. The soil stratigraphy at the site consisted of soft river deposits overlaying interbedded limestone and silt layers of the Pee Dee Formation. Significant pile penetration into the cohesive deposits of the Pee Dee Formation was necessary to generate the required tension pile capacity. The results of the geotechnical investigation suggested that the intermittent limestone layers would cause difficult driving conditions for pre-stressed concrete piles, which are traditionally used in the area. This paper provides an overview of the project, discusses the selection and design processes and installation of the steel OEP piles, and presents the results of the dynamic load testing program conducted to verify the pile design. In addition, measurements of time dependent pile capacity gain and pile plugging made during pile installation are also presented and discussed