Methods to improve karst gaps in Mersin- Anamur highways T3 Tunnel

Within the scope of the thesis, the geology of the tunnel route and its surroundings, tunnel excavation/support classes, interpretation of the improvement method of the encountered karstic cavities, presentation of alternative suggestions and evaluations were examined in the tunnel construction work called T-3 Tunnel in Sipahili location of Mersin-Anamur Highway. Mersin-Anamur-13.Bl.Hd. State Road, Project T-3 Tunnel, covers the area between Km: 142+300-148+875 and the total length of the tunnel is 6575 meters. The maximum cover thickness in the tunnel designed as a double tube is 377 meters at Km: 146+210. The tunnel is a double tube and the road has a platform width of 2x2 and 23-26 m. The route of the tunnel consists of lithologies consisting of karstic crystallized limestone belonging to the Infa-Cambrian aged Sipahili Formation, meta-conglomerate with traces of low-grade metamorphism, pebbly calcschist, phyllite and chlorite schist alternation. A detailed evaluation was made of the behavior of rock masses, the relationships suggested by rock mass classification systems, the variables to be used in tunnel excavation and support system design based on empirical and analytical methods based on literature values, and all the information collected from the field. On the tunnel route, karst cavities were passed between km;148+159.81–148+167.31 and km;148+283.81–148+286.31, where limestone was passed. The improvement of karst cavities was carried out using the lightweight filler concrete method created with a resin-based organic foaming agent.