The improvement mechanism of the mechanical properties of geogrid-reinforced ballast bed remains unclear in existing research.Compression tests of ballast with deformable boundary were conducted.Based on these tests,the coupling method of discrete element method(DEM)and finite differential method(FDM)was applied to establish a refined simulation model for geogrid-reinforced ballast.By combining laboratory tests results with numerical simulations,the impact of geogrid on the macroscopic and mesoscopic mechanical properties of ballast sample was analyzed.The results show that geogrid can effectively enhance the bearing capacity and resistance to vertical deformation of the ballast,with a 50.0％increase in strain energy density.The geogrid can effectively restrict the movement of surrounding ballast particles,reducing the horizontal deformation of ballast bed.Under the same axial stress,the maximum horizontal deformation is reduced by 16.1％,while the horizontal deformation at the geogrid location is decreased by 63.2％.Geogrid reinforced can significantly improve the shear strength of ballast bed,with a minimum 18.8％increase in lateral strength.Geogrid can effectively increase the compactness of the upper tier of ballast bed.Therefore,geogrid reinforcement can be implemented in the sections with ultra-thick ballast beds or unstable foundations.
关键词
有砟道床/格栅加筋道砟/力学性能/离散元/有限差分法
Key words
Ballast bed/Geogrid-reinforced ballast/Mechanical properties/Discrete element model/Finite differential method
维普
万方数据