Geomechanical characterization for tunnelling design along the new railway Kichevo ‐ Albanian border in R. Macedonia

Abstract

The complex geology along the Corridor VIII, section Kichevo‐border of R. Albania requires ten new tunnels. The knowledge of geo‐mechanical conditions as well as a better understanding about the failure process and more accurate rock mass strength estimation are of great importance in order to anticipate likely risks and to recommend the most favourable design of the support sections reducing stability problems of the underground excavations. Several cases of tunnel sections analysing different failure modes have been considered. Stress‐strain analyses are performed by means of the state‐of‐the‐art finite elements numerical models assuming a reliable geotechnical model based on the ground site investigations. In particular the paper is focused on the analysis of the longest and deepest tunnel and the management of the associated geotechnical issues when deep tunnels are excavated in weak rocks. In addition, different working lines are discussed with the purpose of thinking over the most advantageous approaches to assume in tunnelling design in these particular conditions.