RESEARCH ON RESPONSE MECHANISM OF RAILWAY TRACK AND SUBGRADE UNDER THE EFFECT OF OVERWEIGHT GOODS

摘要

The overweight goods is a new concept, which is put forward in recent years with the increase of the traffic volume of the railway. In order to study the response mechanism of railway track subgrade under the action of overweight good, using finite element software ANSYS, a track-subgrade dimensional elastic constitutive model is established to calculate the dynamic response and elastic displacement under the effect of overweight goods. And then we compare the results with the existing design specifications and we evaluate the results comprehensively. The results show that: The stress of rail and sleeper do not exceed the allowable stress value, and the ballast stress exceeds 27.5% more than the allowable value. The transverse and longitudinal distributions of dynamic stress are not uniform, the maximal value is 202.33 kPa. There is an obvious superposition effect among multiple axles. The nearest wheel base of two bogies under the effect of 40 axle load increases by 0.615 m compared with that under the effect of 25 t axle load, meanwhile, the stress at the center of the subgrade surface on the wheelbase decreases by 22.2%. The elastic deformation of subgrade is 1.38 mm. When axle load increases by 10 t, the elastic deformation will increase by around 0.13 mm. The results can provide a reference for future security operations of overweight goods and embankment maintenance and repair of track subgrade of heavy haul railway.