Development of Stabilization Model for Substructure of Railway Heavy Hauls using Prefabricated Vertical Drain

Track stabilization is an indispensable issue in railway track construction within the initial months of track operation. Construction of rail track on soft and compressible formation soils causes pore water pressure to prolong the consolidation time. The passage of heavy haul trains with considerable imposed trainloads over such deposits causes excessive track settlements and significant reduction in the load bearing capacity of the track. It causes deferment in track stabilization. These deformations lead to less safety and stability of railway track systems. As a result, track maintenance will become a challenging concern. This paper presents a proper model of prefabricated vertical drains to be installed in heavy hauls. This model facilitates achieving to a proper degree of consolidation in an optimum time. In this regard, a finite element analysis was carried out to analyze substructure and superstructure of railway heavy hauls. Parameters including subgrade total consolidation time, subgrade degree of consolidation and track’s total settlement have been derived. Consolidation time for subgarde with prefabricated vertical drains has been also established. The number and distance of the prefabricated vertical drains per unit length have been determined. Furthermore, the optimum length of each drain has been identified taking advantage of sensitivity analysis on stabilized track subgrades with different lengths. Finally, a model,including the number, the distance and the length of drains has been proposed in order to install in heavy hauls.