Vertical alignment optimisation in highway design by means of mesh adaptive direct search Available to Purchase

Finalising the vertical alignment of a highway geometric design is a critical phase in a highway project and directly affects its construction cost. Generally, a vertical alignment performed by even an experienced designer and conforming to the specifications is sub-optimum unless it has been modified properly to minimise the earthwork cost. This paper proposes use of the mesh adaptive direct search approach to establish a nearly optimum vertical alignment based on a designer's alignment by moving points of vertical intersections. The method is applied during the design process in a building information modelling environment by a module developed and integrated in AutoCAD Civil 3D software, the aims being to increase the applicability of the method and obtain accurate earthwork volumes. The numerical results showed earthwork costs reduced by as much as 27% by slight adjustments to the vertical alignments of three virtual roads and a real highway project. According to the results, applying the method practically in the design process could save millions in various highway projects.