Influence of anchor head on dynamic response of anchorages

This work deals with the modelling of the dynamic effects of anchor head assemblies of mine bolts and their interfaces with the rock and other components. The load of the anchorage installed in the laboratory was assessed by a non-destructive technique initially using a system based on the application of the impulse load and observation of the frequency response. An anchor head assembly, different from that commonly used, was then deployed as part of tests to assess the load of the anchorages. A dynamic model, developed previously, was used, to replicate the results obtained from the experiments. It was shown that the anchor head model required enhancement in order to obtain the range of frequencies found from the experiments. A set of tests with the more complex anchor head set-up was undertaken in order to obtain the characteristics, in this case stiffnesses, of the anchor assembly interfaces. The sensitivity of different components within the anchor head assembly is discussed showing the influence of the complexity of the head.