Sheetpile Bulkhead Failure Investigation in Savannah, Georgia-PPT Presentation

PPT Presentation

Pdf Summary

The Hutchinson Island ferry landing bulkhead in Savannah began moving on June 18, 2022. After cracks appeared in the pavement, the wall moved about another foot that afternoon, damaging monitoring equipment and toppling a ticket stand. Over the following two weeks, it shifted 8–10 feet, while the ground behind it settled 6–7 feet. The movement pushed against the ferry’s guide piles and crushed the floating dock, prompting the ferry service to stop.<br /><br />Engineers judged the nearby Convention Center and Westin Hotel safe because they were pile-supported, but the dock was unsafe. With access from land restricted and the plaza unable to support heavy equipment, crews stabilized the wall using steel struts connected to existing guide piles. Work was carried out from a barge.<br /><br />The collapse was most likely caused by several interacting factors, not the small earthquake that occurred about four hours beforehand. The bulkhead had been built over a former slip where excavation left 5–15 feet of soft mud beneath the fill. As this soil settled, the fill and pavement added loads to the wall’s helical-pile tiebacks. Those anchors, installed in clay, could creep over time; because they acted individually, failure of one could overload neighboring anchors in a “zipper effect.” The investigation concluded that this was a local structural failure, not a global stability failure: the sheet piles were deep enough, but they yielded under excessive bending.<br /><br />The replacement design used a new sheet-pile wall, pile-supported deadman tiebacks, and a pile-supported relieving platform to carry plaza loads. Tie rods were placed in PVC casing to accommodate settlement. The presentation emphasizes the importance of accounting for buried soft soils, ground settlement, and tieback-system behavior in design, and of making rapid, coordinated engineering decisions during infrastructure emergencies.

Keywords

Hutchinson Island ferry landing

Savannah bulkhead collapse

sheet-pile wall

ground settlement

soft soil

helical-pile tiebacks

structural failure

ferry service shutdown

barge stabilization

replacement design