Laboratory Investigations on the Mode of Failure in Frictional and Low-Cohesive Materials Under the Load of a Ground Anchor

Abstract

Ground anchors are widely used in many types of construction works, such as stabilization of rock slopes, wind turbines, concrete dams and bridge towers. Some of the modes of failure for these anchors still have an insufficient scientific basis, and that applies especially to what happens in the ground when overloaded. This paper presents investigations on the failure development in frictional and low-cohesive materials which are subjected to loading by an embedded anchor with a free length towards the surface. The failure development is demonstrated through a series of small-scale physical model tests performed in the laboratory. The physical model setup consists of a transparent PVC test chamber, a rigid «anchor block», and a hydraulic jack. The model is instrumented with a camera, an extensometer and a load cell to continuously record the failure development and resistance from the material as the anchor block is pushed through the sample material. The main question investigated is how the failure appears, as a failure along the whole pull-out body at once or as an advancing fracture along the plane, where in the first case the shear capacity of the material will be the main input in calculations, and for the second case, one also needs to take failure propagation into account.