The Relation of the Method Used in Tunneling Operations with the Geological Structure Example of the Black Sea Coastal Road

Abstract

Transportation tunnels are the most preferred method to facilitate transportation in mountainous and rough terrains. The excavation method and the choice of fortification tools in tunnel construction depend on the geological structure of the tunnel route. Correct formation determination and determination will reduce the cost and eliminate many risks. The Black Sea region has a very mountainous and rugged terrain. The most obvious method used to overcome rough terrain is road tunnels. The rock classification of the tunnel route and the support to be formed accordingly are very important in the selection of the method to be applied in the highway tunnel constructions. Within the scope of this study, Trabzon-Akyazi region, which is an important part of the Black Sea coastal road, was studied. The geological formations on the route of the 3-lane and double-tube tunnel with a length of approximately 2476 meters, which is planned to be built within the highway passing through this region, were examined and the method used in the tunnel construction was determined. As a result of the analyzes and calculations, it has been determined that the dominant unit along the tunnel routes is the agglomerate of the Besirli formation and the New Austrian Tunneling (NATM) method is applicable. The rock classes found were determined to be B3 and C2 classes according to NATM. Excavations in the tunnel were carried out by drilling and blasting method in the form of the upper half and the lower half.