A review of methods for modelling drystone retaining walls

Drystone walls are durable structures, owing to their intrinsic ductility, permeability, and the strength of the materials used. Nevertheless, they can be subject to slow deterioration, caused by weathering of the materials, by the application of loads for which they were not designed, by impact, or by inappropriate repair methods. It is then necessary to assess the condition of the structure, and to repair or to replace the construction. This paper aims to bring together advances on drystone retaining walls made by researchers in France and the UK over the last two decades. Three methods that are used to evaluate the stability of drystone retaining walls are summarised and compared: the distinct element method, limit equilibrium analysis and yield design analysis. The first proves to be most suited to back-analysis, while the second and third methods may also be used for design. The paper describes the use of design charts, an example of which is presented. These charts were based on the understanding obtained from these models, which has now been confirmed by full-scale testing.