Centrifugal Modelling of Riverbank Failure

Pilot tests were first performed on kaolin models, and then further tests were carried out on models made from undisturbed block samples taken from the site. The investigation described was limited to a study of the individual and combined effects on the riverbank stability of dredging of the riverbed, flooding and drawdown, and heightening of the retaining wall. Although no visual collapse occurred in the block samples under field conditions, measuring techniques developed at Cambridge University enabled the study of the displacements and strains within the models, leading to identification of the failure surface. The fact that the model slope mechanism of progressive failure, and stability analyses carried out on the preceding surface, using laboratory obtained strength parameters, show that this mechanism leads to a decrease in safety factor from 1.2 to 0.9. It is concluded that although progressive failure may not be able to develop fully in the centrifuge, the failure surface may be identified using special measuring techniques.