Uplift behavior of under-reamed anchors in sandbed

Under-reamed anchors are used in construction fields to provide increased pullout resistance that enhances the stability of various structures, including offshore structures. Under-reamed anchors are composed of a reamed plate part and a friction part. In this study, a series of laboratory model tests was carried out in sand to investigate the pullout capacity of an under-reamed anchor. Instrumentation was employed to determine the separated resistances undertaken by the shaft portion and the reamed plate of an under-reamed anchor. Based on the test results, it was found that the pullout resistances of the friction part and plate part of an under-reamed anchor were smaller than those of the friction anchor and the plate anchor, respectively.