Modeling Reinforced Ballast Underneath Railway Using Finite Element Method

Résumé

Ballast provides a firm and stable platform, and support sleeper uniformly with high bearing capacity, can be improved using reinforcement at different spacing. The main purpose of this study is to evaluate the degree of improvement in bearing capacity of the ballast layer underneath railway using geogrids as reinforced materials. To study the effect of ballast thickness, mechanical properties of soft soil undrained shear strength and modulus of elasticity E, reinforcement by using Geogrid layer, a Three-dimensional finite element analysis program (ANSYS v.11.0) was adopted. It is concluded that Presence of geogrid layers leads to reduce the vertical displacement (settlement), while the corresponding load carrying capacity increased significantly. The uniformly oriented geogrid and its ability to improve soft soils cause an increase in the load carrying capacity. This was combined with the ability of ballast layer to sustain larger compressive force at advanced stages of loading. It is noticed that Theoretical solution using ANSYS Finite Element program can be adopted in the evaluation of loads and the amount of settlement for the soil layers beneath the railway lines as well as Ballast .The program gives good correlation and a sufficient degree of convergence in behavior.