Expander bodies as ground anchors : Broms, B B; Nord, Ground EngngV18, N7, Oct 1985, P19–23

Abstract

A new type of ground anchor, the expander body anchor, has been developed by Atlas Copco MCT, Stockholm, Sweden. This new anchor consists of a folded thin steel sheet, the expander body, which is inflated in the ground. The anchor is placed in a predrilled hole. The new anchor can be used to support a sheet pile or slurry wall, to increase the stability of slopes or to resist the high uplift pressures acting on dry docks, subway stations and hangars. The ultimate tensile strength of the new ground anchor can be evaluated from the maximum grout pressure required for the inflation of the expander bodies or from the results of different penetration tests (cpt, spt or wst). The ultimate tensile resistance of the new anchor has been tested in different soils in Sweden and compared with that calculated from the results of penetration tests (weight soundings), the undrained shear strength of the soil as well as from the maximum grout pressure required for the inflation of the expander bodies. The proposed calculation methods were found to give results which in general are conservative and safe.