Experimental and Numerical Study of Uplift Behavior of Shallow Circular Anchor in Two-Layered Sand

In this study, the behavior and scale effect of shallow circular anchors in two-layered sand is evaluated by comparing the results of a conventional 1 g model test with the results of finite-element analysis. The finite-element analysis is performed using an elastoplastic model in which progressive failure with shear band effect is introduced into the constitutive equation. The model is able to successfully predict the anchor behavior in two-layered sand. The direction of shear band propagation, within a sand layer, was observed to be a function of the density alone, regardless of the position of the layer. When the thickness of the lower layer was increased, maximum uplift resistance was found to increase with increasing thickness of a dense layer above a medium bed, and to decrease with increasing thickness of a medium layer above a dense bed. The scale effect was remarkable in the lower layer of dense sand.