Sheetpile Bulkhead Failure Investigation in Savannah, Georgia

The Hutchinson Island ferry landing, a vital transportation hub located between the Savannah Convention Center and Westin Hotel, faced a critical infrastructure challenge on June 18, 2022, when the sheet pile bulkhead along the Savannah River experienced movement, resulting in a substantial crack in the brick-paved plaza. Immediate monitoring efforts commenced within two hours of the bulkhead disturbance, revealing progressive movements over the subsequent two weeks, leading to approximately ten feet of deflection and six feet of settlement behind the bulkhead. Subsequent repair work involved the extraction of 65-ft-long steel sheet piles. This investigation embarked on a meticulous review of the original design and construction procedures, followed by a comprehensive subsurface exploration program. The steel sheet piles were originally supported by drilled helical anchors, and the failure mode and pattern were closely scrutinized. Analysis of the pulled-out sheet piles revealed consistent shape and yield points. Computer modeling was conducted to replicate the actual deflection profile and yield point as verification of the soil parameters and design models. This paper presents the investigative findings, including an analysis of subsurface conditions and the most probable causes for the bulkhead failure. The results of the investigation have been instrumental in formulating design recommendations for the repair of the bulkhead system. By shedding light on the root causes of the failure, this research contributes valuable insights to the soil-structure interaction in the steel sheet pile design.