Modelling of debonding along the fixed anchor length

Debonding of the fixed length of ground anchorages is presented, concentrating on the failure behaviour of the bond at the proximal end of the fixed length. The dynamic effects of debonding along the fixed length are discussed in particular, with specific reference to dynamic testing. The static effects in terms of load distribution are also reviewed by comparing pull out tests undertaken on laboratory anchorages bonded using resin grout to results from a bond model included in a dynamic model. Bond models, which allow the dynamic effect of the debonding to be observed, are proposed for inclusion in the dynamic model. These models are an elastic–plastic yielding model with some residual load capacity and a model with reduced stiffness once the plastic-yielding regime has been entered. Simulations of an anchorage system including these bond models show both a change in load distribution and a drop in the first natural frequency due to debonding. Simulation of a case study is undertaken using the model and the results show good agreement with the measured field data.