ABSTRACT

The project area regarding its geological characteristics is included in the central part of the Black Sea Region. While the eastern portion of the Black Sea Belt is mostly represented by volcanic rocks, the western part is dominated by sedimentary rocks. In this frame,

ABSTRACT: The Ordu province in local scale and northeastern Turkey in regional scale comprise of volcanic arc related rock masses. These modes of origin accommodate both volcanic and flysch type rock masses that have transitions so often with each other. The Boztepe tunnel will mostly be driven through this type of lithology. In order to assess the rock masses surrounding the tunnel from a geotechnical point of view; surface, subsurface and laboratory investigations have been implemented. Internationally accepted rock mass classification systems (RMR, NGI-Q-system and GSI) have been utilized via information gathered mostly from surface geotechnical investigations. In an attempt to check the validity of the empirical tunnel supports, stress analyses around the tunnel openings have been executed through employing finite element analyses by the Phase2 package program. Kinematical and limit equilibrium analyses of the tunnel portals have been employed for portal slope stability considerations.