Détermination expérimentale d'une loi de tassement du ballast des voies ferrées soumises à un chargement latéral

Abstract

A one-third scale bench test representing a portion of railway track has permited to determine a lateral settlement law of the ballast. The experimentation uses a two-block sleeper with ballast and with elastomeric or wood representing the soil. A jack exerts the same signal as the train. Two similitudes have been tried with the bench test. The first one conserves the volumetric mass of the ballast and the stresses just under the blocks, and the second one conserves the volumetric mass of the ballast and the acceleration. Measured settlements are different in the two cases of similitude. From this it may be deduced that one phenomenon is responsible for the settlement: vibrations. We have identified two laws for the lateral settlement of the ballast: one for a few cycles and another one for a lot of cycles. The sum of these two laws can describe the whole behaviour of the ballast. These laws are in accordance with the measurements made on track.Key words: ballast, settlement, experimentation, reduced scale, railroad track.