THE MECHANICS OF INFLATABLE ANCHORS IN COHESIONLESS SOIL

Tim Newson, Sean Hinchberger and Yi Liang

ABSTRACT: This paper describes an investigation into the performance and pullout capacity of an inflatable anchor system. The anchor system comprises a hydraulically inflated rubber membrane or packer that may be bored into place and then inflated to provide pullout resistance. A series of scaled physical model tests were used to study the anchor performance and pullout capacity. The model tests were done in a calibration chamber using cohesionless sand and anchors of various length, diameter, embedment depth and inflation pressure. The anchor behaviour during pullout is interpreted using finite element analysis that accounts for non-linear soil behaviour, inflation and subsequent deformation of the inflatable membrane, and anchor-soil interaction. The scaled model tests and interpretations assist with identifying the dominant mechanisms affecting the pullout capacity of inflatable anchor systems.

Key words : Finite Element Method, inflatable anchor, pullout capacity, sand (IGC: E4)