EVALUATION OFALTERNATIVE TRACK ALIGNMENTS ON WHOLE LIFE COST OF LOT 11 SECTION OF THE AWASH-WELDIYA RAILWAY LINE

Geometric design is an essential and major component in the design development of railway projects. Geometric alignments (horizontal and vertical) affect project cost and safety significantly keeping other factors constant. The effect of track alignment on cost of awash-weldiya railway project in particular to Lot-11 stretch is evaluated in this thesis. Three different horizontal and vertical alignments are designed and their respective costs computed and compared. In the design process, topographic data is generated from 30m Resolution Digital Elevation Model using Global Mapper software. Horizontal and vertical alignments are designed using widely applicable Bentley Rail Track (BRT) software. In this thesis, Ethiopian Railways Corporation manual is used as governing rail standard. Basic techniques are applied for economical and safe design of the project. Generally, a minimum curve radius of 2000m and a maximum gradient of 2% is applied but a deviation from the standard is made in some parts due to topographic and other constraints. Accordingly, horizontal curves as low as 500m and gradient as high as 2.5% have been used in some places where there is topography constraint