Flexural behaviour of a clay layer: experimental and numerical study

Solid waste landfills consist of a cover barrier that often includes a compacted clay liner. However, this barrier can encounter numerous problems, in particular those related to in situ implementation and to mechanical loading that may cause stress in the clay layer, leading to the development of cracks. Tensile stress damage and shearing bands are often observed. To characterize the behaviour of a clay in tension, four-point bending tests attempting to reproduce conditions of implementation were carried out in the laboratory. At the same time, original large-scale bursting tests were carried out in the field for validation. To interpret these results, a numerical simulation was used, which was calibrated with laboratory results and then applied to large-scale bursting tests. This simulation was then used to simulate the flexural behaviour of the cover barrier. By focusing on the most critical case, the numerical simulation is able to predict the initiation of cracks.