Experimental assessment of dry stone retaining wall stability on a rigid foundation

Dry stone masonry retaining walls are present in the majority of mountainous areas all around the world, but the technique is marginal today in developed countries. The emergence of the concept of sustainable development calls for renewed use of this technique, both for the repair of existing retaining walls and the building of new ones. The objective of this research was to seek the knowledge necessary to ensure the stability of these structures, using experimental investigations in the laboratory and in situ. From this work, a model has been developed for calculating the stability of dry stone retaining walls. After laboratory testing to quantify the interface friction, the data obtained were used in a model based on the equilibrium of the forces at failure. The model considers the possibility of the internal failure of the wall, taking into account the irregularity of the geometry of the stones and of their arrangement, using a parameter determined by in situ experiments. Full-size on-site experiments on 5 walls (2 and 4 m high), loaded using hydrostatic pressure, are presented. These allowed quantification of the parameters of the model, and its validation for two types of material. These tests also determined the limits of monolithic behaviour of the masonry, thus defining failure and enabling the fulfilment of practical engineering requirements.