Research on dynamic mechanical behavior of ballast bed in windblown sand railway based on dimensional analysis

Abstract

Railway operation is faced with windblown sand hazards in desert areas. In order to study the influence of sand intrusion on dynamic mechanical behavior of railway ballast bed, a multi-scale discrete element model of sleeper-ballast bed-surface layer of subgrade has been established with the method of “step filling-particle replacement”. The vibration acceleration of the ballast bed and the dynamic displacement of sleeper field tests in the section with severe sandstorm have carried out to verify the correctness of discrete element analysis model. The scale invariance of the linear contact model and the rationality of the scaling of the sand size are explained by the “dimensional analysis method”. The results show that the sand intrusion reduces the vibration of ballast bed. When the sand content reaches 30%, the vibration and elastic deformation of ballast bed decrease by 94.2% and 63.2% respectively. The invasion of sand can reduce the deformation of the surface layer of subgrade, and the maximum reduction is 53.3%. Therefore, it is necessary to pay attention to the service state of ballast bed with sand content of 30% in windblown sand area, and make the maintenance plan reasonably.