Geotechnics of Karabuk Kısıklı tunnel

Engineering geology fundamentals have an essential role in geotechnical design of linear engineering structures especially in tunnel engineering. Cildikısık Tunnel Crossing has been a great source in defining this role in terms of engineering geology. The findings, from the field, obtained through only geological investigations have lead to remarkable changes in the existing tunnel project that is to be applied. The new project, which has been proposed through this study as an alternative to the existing, has resulted in important gaining in the overall construction. The project turned to be much safer, economical with regards to construction expenses, and environmentally friendly. The achievement has been due to the use of engineering geology fundamentals in the use of well known rock mass classifications/definition systems such as; RQD, RMR, Q-System and GSI. The role of Water ? Discontinuity Clay trinity in the use of such systems and in the determination of geotechnical design parameters has been clarified. As a result, it was pointed out that none of the existing systems alone is sufficient to make precise evaluation of the rock mass geotechnical design parameters. With the proposed project for Cildikısık Tunnel Crossing, which has been based upon this approach, has provided 75% of reduction in support systems and density, besides, it has lead to increase in traffic safety. The, environmental gaining is on the other hand is invaluable. The canyon before the tunnel inlet has been saved from being completely filled by earth material which would make it irrecoverably destroyed.