Une nouvelle méthode de prédiction de fontis grâce à une modélisation par poutres plastiques

ABSTRACT The increase of the subsidence towards the surface of the ground is a rather complex phenomenon, responsible for damage to the works of surface located in their influence. Many approaches were developed, but the modelling of this phenomenon encounters theoretical and practical limitations. The approach suggested in this paper makes it possible to provide a pragmatic diagnosis using the plastic theory of beam. It is a simple and frequent approach in Civil Engineering. Two points were developed: the rigidity of the layers and the taking into account the elastoplastic behaviour of the strata. An inter-comparison between the results of the new approach and those using the numerical modelling (Distinct Elements Code) made it possible to validate the method suggested. Finally the application to the study of the behaviour of the benches on the roof of an underground cavity shows the operational and practical character of this new method.