In this study, applicability of the excavatability classification systems in underground excavations is investigated. For this purpose, the entrance portal of the Konakönü (Araklı-Trabzon) tunnel, excavated in volcanic rocks within the scope of Black Sea coastal highway project, is chosen as pilot study area. The entrance portal of tunnel is excavated through  the rocks of Eocene-aged Kabaköy formation of basaltic-andesitic tuffs, aglomerate and basalt.