Analysis Of Enhancing The Performance Of Ballasted Railway With Geogrid Using Abaqus - A Case Study Of Addis Ababa Project

Abstract

One very important issue is the need for significant improvement of railways passing over areas of poor soil conditions due to continuous deformation and a low bearing from the ballasted foundation. One general problems happened under substructure are vertical settlement and lateral settlement of the layers. In order to minimize these problems enhancing the bearing capacity of the subgrade soils can be the major solution. The subgrade soils is known by poor bearing capacity, high plasticity and high swelling factor. It is called black cotton soils. So, the bearing capacity of the soils can be improved by geotechnical ground improvement. Hence, geogrid reinforcement is used as a method of improving the performance of the railway tracks. Therefore; geogrid is reinforced in between Ballast and subballast to minimize the layers vertical settlement and to minimize track lateral spreading of the materials. ABAQUS software package is used as a tools in analyzing the finite element models of a half of ballasted railway structures. Hence, a model embankments were simulated numerically using finite element procedures. Further numerical simulations were then performed on ballasted embankments reinforced with and without geogrid to model accurate ballasted track conditions and the effects of confinement on performance. The numerical simulations demonstrate that geogrid reinforcement effectively decrease vertical settlement and increase lateral confinement of a ballast embankment. The results suggested that vertical deformation of ballasted railway is reduced by 17.79%, when geogrid is reinforced in between ballast and sub-ballast, and due to the reinforcement of geogrid on ballasted track the lateral deformation of the track was rather stabilized to 50.89%. The use of geogrid in ballast stabilization could demonstrate to a sustainable solution for a common and expensive problems of poor subgrade soils.