Yield design approach to uplift bearing capacity of shallow rectangular plate anchors

Resumo

Plate anchors are a widely used class of foundation systems for structures subject to uplift forces. Its
bearing capacity evaluation has been object of constant revisions in literature, notably as a result of the recent
decommission operations of large offshore structures. In this context, the present paper aims to evaluate the uplift
resistance of shallow rectangular plate anchors based on the theoretical framework of limit analysis and its related
kinematic approach. Upper bound estimates of the collapse load are obtained from a class of failure mechanisms
considering generic discontinuity surfaces defined from the functional minimization of the uplift bearing capacity.
The rock is modeled as a Tresca material with a tension cut-off criterion, whereas the lower interface of the anchor
exhibits a tensile stress threshold. A parametric study is conducted to evaluate the effect of the problem main
parameters, allowing for an estimate of the ultimate pullout force for several cases. Finally, the semi-analytical
predictions obtained are compared with available results in the literature, thus validating its application. Results
show that model predictions are in good agreement with available results for plates with low embedment ratios.
The dependence on the tensile stress limit of the Tresca material and the interface resistance are also highlighted.