Uplift behaviour of cylindrical anchors in sand

Abstract

A series of laboratory model tests and numerical analyses has been carried out to study the behaviour of vertically embedded cylindrical anchors in sand. Due to the cylindrical shape of the anchor, both the shaft friction and the end resistance have substantial contribution to the pullout capacity. But shaft friction and end resistance do not reach peak values at the same anchor displacement. As a result, analyzing the anchorage behaviour of cylindrical anchors is complicated. The pullout behaviour of the anchor is significantly influenced by the embedded depth. There exists a critical depth (about seven to eight times the anchor diameter D) which differentiates the behaviour of a deeply embedded cylindrical anchor from that of an anchor with shallow embedment. The complete load-displacement relationships for shallow and deep anchors can be simulated by the numerical analysis proposed herein. A minimum horizontal spacing of 10D is needed between neighbouring cylindrical anchors to be free of interference.Key words: cylindrical anchor, uplift behaviour, laboratory model test, numerical analysis, sand.