Behaviour of the clay cover of a site for storing nuclear waste of verylow activity submitted to differential settlement of underlying waste:laboratory and field bending tests

The behaviour of the cover barrier of a site for storing nuclear waste of very low activity is studied. The risk of a bending of the clay layer in case of differential settlements within underlying waste is particularly studied. Laboratory and field bending tests are performed. Influence of the water content on the mechanical behaviour of the clay is examined. Initialization and propagation of cracks are studied. The limit value of the extension strain of the clay layer without cracking is characterized. Results of field and laboratory bending tests are presented. The main aim is to optimize the use of clay as landfill cover, in terms of conditions of implementation (water content, compaction energy).