Sheet Pile Wall Failure Case Studies: Causes and Lessons Learned

Cantilever and anchored sheet pile bulkheads are routinely used for retaining the backfills and excavations in marine engineering. Furthermore, as the global economy becomes increasingly integrated, the necessity for larger container vessels and port capacity rises. The sheet pile walls are critical to enabling the construction of modern facilities necessary to attract these ships that are vital to the economic health of the ports to allow the harbor bed to be dredged to depths required by modern vessels or support the upland. However, many sheet piles fail due to high stress and/or loss of long-term serviceability. An appropriate analysis and design method and proper understanding of sheet pile walls’ behavior can prevent the occurrence of such failures significantly. In this paper, first, several case studies of sheet pile wall failures collected from the inspections at the ports and other marine structures are presented, and probable causes are discussed and evaluated using lateral load analysis. Next, both embedment depth to ensure the stability and maximum bending moments are predicted based on three different methods: finite element, P-Y model, and limit equilibrium method (LEM). These three methods are widely used in the marine industry for analyzing sheet piles, and several software has been developed in the past based on the aforementioned methodologies. Results suggest that identifying the possible failure of the sheet pile walls is critical in the design. Also, results indicate that sheet pile response predictions based on the P-Y model and finite element methods are greater than the corresponding values from the LEM, depending on the soil parameters, sheet pile stiffness, and anchorage condition. The location of the fixity obtained from both finite element and the P-Y methods was found to be consistent. Some increase in bending moments and embedment obtained by the LEM may therefore be warranted depending on the wall boundary conditions and soil parameters. Furthermore, it was found that many sheet pile wall failures can be attributed to improper analysis methodology and/or overlooked design details and the site condition.