This work on the densification of a granular medium under horizontal vibrations was realised in the context of an industrial study on sand in fuses, undertaken by the firm MERSEN. The scientific purpose is the understanding of the mechanisms involved in horizontally vibrated granular media. Both experiments and computer simulations were used. Experiments were conducted with 500 µm silica grains. Sinusoidal accelerations up to 10 g were applied to a container of a few centimetres using frequencies between 20 and 200 Hz. The experimental device enables instantaneous force, acceleration, grain velocity on the walls (PIV) and mean bulk density to be measured. Discrete element method (DEM) was used for the computer simulations. Specific techniques were developed to analyse the results and compare them with experiments. Computer simulations provided data which are not experimentally available such as local values of density, velocities and stress inside the particle packing. In the case of an open container, simulation results are in good agreement with experimental ones (convection rolls, thresholds, effect of acceleration...). Original results are obtained in both experiments and simulations, such as a grain velocity increase with the container length. Simulation provided specific results such as the effect of friction coefficients on the direction of rotation of convection rolls and the characterization of stress inside the particle packing. The flowability of grains across circular holes of various sizes was also studied. The behaviour of sand in a closed container (confined medium) was studied during a progressive filling. Significant differences were observed when the filling rate becomes high. The dissipated energy and the apparent mass of the vibrated device were defined and measured using acceleration and force measurements. Specific models were built to analyse and understand the observed behaviour. Some results on the filling control were patented by MERSEN.