Seismic Influence on the Behavior of Cantilever Sheet Pile Walls Under Strip-Type Loading

Abstract

The dynamic response of cantilever sheet pile walls under strip surcharge loading and seismic activity is critical in earthquake-prone regions, emphasising the effects of distance, width of the surcharge, and seismic motions. The numerical analysis is being carried out in FLAC2D using a finite difference formulation to simulate a cantilever sheet pile wall installed in a liquefiable sand layer described by the UBCSAND model, resting on an underlying non-liquefiable layer characterized by the Mohr–Coulomb constitutive relationship. The backfill model included a strip load with variable width (0–4 m) and variable spacing (0–4 m) from the top of the wall, with a uniform surcharge of 20 kPa. Three significant seismic motions were analyzed: the 1994 Northridge, 1989 Loma Gilroy, and 2001 Bhuj earthquakes. Model performance was evaluated by comparing results with experimental results, demonstrating consistent trends in lateral displacement, bending moment distribution, and excess pore pressure development. It was observed that the maximum top displacement of the wall reduced from 1800 to 1660 mm with increased distance from the wall, while the maximum bending moment along the wall varied, reaching 211 kNm/m at a distance of 0 m for the Northridge motion. The study highlights the significant impact of strip surcharge loading on earth pressure distribution and liquefaction effects, providing valuable insights for designing and analyzing sheet pile walls in areas prone to seismic activity. © The Author(s), under exclusive licence to Indian Geotechnical Society 2026.