Numerical modelling of full-scale tests on drystone masonry retaining walls

The behaviour of four drystone masonry retaining walls of different geometry has been modelled numerically using the discrete element code UDEC, and the results have been compared with the field trials carried out by Burgoyne in Ireland in 1834. By using appropriate soil and wall mass densities, strengths and stiffnesses, it was possible to reproduce in the numerical analyses the field behaviour observed by Burgoyne. Reasonably close agreement was obtained between the horizontal components of earth pressures calculated in the numerical analyses and using the earth pressure coefficients given by Caquot and Kerisel. Basal stress distributions calculated using the condition of equilibrium of the wall were also broadly consistent with those resulting from the numerical analyses. The results also confirm both the influence of the geometry of a drystone masonry retaining wall on its performance and ultimate stability, and the soundness of Burgoyne's engineering judgement in specifying his programme of field tests.