Failure and Deformation Mechanisms of Vertical Plate Anchors Subjected to Lateral Loading in Sand

This paper presents an experimental study on the pullout behavior of a vertical plate anchor buried in sand under lateral loading, using the digital image correlation (DIC) technique. Based on image analysis, the influences of anchor embedment ratio, sand relative density, and sand–plate interface friction on the failure and deformation mechanisms were discussed. With lateral displacements, the plate anchor experienced passive soil pressure in the front and active soil pressure from the behind. It is observed that the passive failure surfaces varied from approximately linear to be curved and finally became locally rotational with increasing embedment ratios, which indicated that the failure mode transitioned from general shear to be local shear gradually. The failure process is progressive in nature, and the critical embedment ratio is sand-state dependent. With an increasing relative density of sand, the front passive failure zone became larger, whereas the scope of the active failure zone reduced. A wider range of soil may be mobilized by plate anchors of a greater interface frictional strength, leading to enhanced anchor capacity, and this effect decreased with increasing anchor embedment ratios and vanished for deep anchors. The test findings can provide useful visualized data for the development and verification of relevant theoretical models.