双转向架荷载下郑万铁路泥岩路基段动力响应分析OA

The dynamic response of subgrade under the vibration load of high-speed railway train was studied by means of physical model test.Based on the non-Hertzian contact theory and two-dimensional Gaussian distribution,the nonlinear stress distribution in the contact spot generated by the wheel load on the wheel and rail was simulated in Abaqus by Fortran language programming.Through the comparative analysis of numerical simulation and physical model test results,the rationality of the above high-speed train load simulation method was verified,and the stress and displacement time history curve characteristics of subgrade soil unit under two kinds of bogie spacing excitation forms were analyzed.The results show that under the action of train load,the dynamic stress of subgrade is mainly vertical compressive stress,which is distributed in M type along the subgrade section,and the maximum value appears at the edge of track slab,and the dynamic stress,dynamic strain and dynamic displacement are greatly improved with the increase of axle.With the increase of subgrade depth,the dynamic stress,dynamic strain and dynamic displacement under different axle excitation forms gradually decay,and the influence of train load is more significant in the shallow surface layer of subgrade(2 m depth).The subgrade between bogies with larger spacing(17.5 m)appears the phenomenon of instantaneous upward dynamic deformation caused by the superposition of stress direction upward and dynamic stress,while the bogie with spacing of 7.5 m will not appear this phenomenon.