Undrained Uplift Capacity of Square and Circular Plate Anchors Embedded Near Clayey Slope

The decrease in undrained uplift capacity of horizontally placed square and circular plate anchors due to presence of a nearby saturated undrained clayey slope has been analysed using 3-D elastoplastic finite element method for non-homogeneous as well as homogeneous clay. The uplift capacity has been calculated considering the anchor plate being embedded at different distances (s) from the crest of the slope starting from zero to a finite value where there is no effect of the slope. The different parameters like embedment ratio (H_a/B_a), slope inclination angle (β), normalized cohesion (c_u0/γB_a) and the normalized value of increment rate of cohesion with depth (r_c) have been examined for their influence on the undrained uplift capacity. The study confirmed that an increase in slope inclination angle leads to a continuous decrease in the plate anchor’s uplift capacity. The effect of the slope, however, reduces significantly when the anchor fails by local yielding. A reduction factor (η) has been used to describe the decrease in the undrained uplift capacity. Increasing the distance of the plate anchor from the slope crest up to a certain optimal value (s/B_a)_opt results in a higher reduction factor (η) after which the value of η becomes constant and beyond that distance there is no effect of the slope.