Construction Cost Estimation for Greek Road Tunnels in Relation to the Geotechnical Conditions

The accurate assessment of a tunnel construction’s basic cost is of major importance of the entire financial appraisal of the overall project. Thus, efficient tools and analyses addressing this particular issue can provide significant information (even from the preliminary stages of tunnel design) and assist in the whole decision making process throughout the project’s design life. The paper presents the analysis of tunnel construction cost with respect to the excavation process and the temporary support measures used. These support systems have been determined to be the most influential factors when assessing the total cost of the tunnelling project. More specifically, the analysis is based on the data gathered from the construction of 5 Greek road tunnels, where the construction cost has been estimated from respective crosssections representative of a variety of geotechnical conditions. The assessment is made to reflect current unit prices (2011), so as to establish a common reference point for all tunnels under evaluation. Cost figures are presented in terms of cost per meter (€/m) and cost per cubic meter (€/m3). Consequently, the findings of the analysis could be used as a preliminary construction cost estimation tooling in order to provide design engineers and project managers a rapid and representative estimation that can be in other similar underground construction projects in Greece and perhaps similar construction projects internationally.