ABSTRACT
Terzili tunnel is a double tube highway tunnel with a length of 1180 m each tube. The conventionally excavated tunnel is located in Ordu-Türkiye (Blacksea region) and is constructed mainly in highly weathered, very weak, fractured claystone and clay. Generally, the tunnels are supported by rigid support systems, by means of shotcrete, steel sets, self-drilling IBO bolts and umbrella steel pipes and the excavation has been performed staged by top heading, benching and invert. Between the chainages Ch 32+670 and 32+677, the left tube crown was reaching out of the natural topographical surface due to a river and the overburden above the right tube was around 2 meters. This paper presents the design methodology and successful site construction application of the shallow river passing section.
