Structural analysis and design method for subgrade bed of heavy haul railway

Based on the proximity of the rigid wheel base of a heavy vehicle to the distance of adjacent bogies of the adjacent two cars, the load characteristics of heavy haul railway subgrade structure under the single, double and four axle load mode were discussed. According to the relationship between load threshold (long-term strength) of subgrade structure cumulative deformation in the state of convergence under cyclic loading and foundation coefficient K30, the technical conditions of heavy haul railway subgrade structure to maintain good service performance under the heavy axle-load, long consist, high-density transportation environment were studied. The design and calculation methods of heavy haul railway subgrade structure that could satisfy the technical requirements of structural strength, bearing stiffness and long term stability were concluded. Studies have shown that there was a significant multiaxial additive effect that will significantly increase the depth of the dynamic stress of subgrade. The four-axis load mode that considers adjacent bogies of the adjacent cars is recommended for heavy haul railway subgrade. The thickness of the surface layer of the subgrade with graded broken stone should be changed with the change of foundation coefficient K30 of the subgrade bottom layer. © 2016, Science Press. All right reserved.