Geotechnical aspects of the Mid-West Rail Upgrade Project in Western Australia

This paper presents a description of the geotechnical aspects associated with the design and construction of the MidWest Rail Upgrade project in the Mid-West region of Western Australia. It covers aspects of site investigation on existing track formation and track duplication alignments, assessment of the capacity of existing bridge foundations, methods for assessment of the suitability of existing rail formation and upgrades required, analysis of railway behaviour in salt lake areas and recommended ground improvement schemes as well as design of formation-to-bridge transition zones. The paper presents results from a constructability study carried out to assess the stability of existing operational track during the construction of duplicated portions of the line. It also describes the methodology and results of borrow source investigations for both main sections of the project and geotechnical related issues that arose during the construction stage.