Seismic Response of Anchored Sheet Pile Walls by Centrifuge Modelling Tests

Sheet pile wall systems have been widely employed in excavation, waterfront structures and retaining structures due to their outstanding advantages of low costs and favorable construction conditions. Taiwan is located in an active seismic zone, where earthquakes regularly occur. Therefore, a series of centrifuge tests was conducted in this research to study the behavior of sheet pile walls at riversides subjected to dynamic loading. A model was constructed via the pluviation method with fine quartz sand at a relative density of 70%. The results indicated that the displacement and tilting angle of the wall without anchors (SWA) remained in the near-collapse zone under 0.16 g seismic loading. In contrast, the single-anchored wall (SAS_0.32) and double-anchored wall (DAS_0.64) collapsed under 0.33 g seismic loading. However, the wall with two anchor rows (DAS_0.32) with the same anchor tie rod spacing as that of the single-anchored wall remained stable under severe seismic loading (0.45 g). Consequently, compared to the single-anchored wall, the double-anchored wall reduced the bending moment by half at a location of 0.66H to 0.88H below the top of the wall instead of 1.1H without anchors. Moreover, the lateral displacement, tilting angle, bending moment, and backfilled settlement were one-third lower than those of the single-anchored wall (SAS_0.32) if the anchor spacing of the double-anchored wall (DAS_0.64) included the same number of anchors. The arrangement of the anchor row significantly affects the history of the anchored force, which is 1.74 times the anchored force of a single anchor (SAS_0.32) under seismic conditions. Consequently, with the same number of anchors, the double-anchored rows contribute more effectively than the single-anchored row to the stability of the retaining structure.