Record Spans with Prestressed Concrete in Turkey: DSI Group at Work on a Bridge Construction Project, Guelburnu Bridge, Turkey

Record Spans with Prestressed Concrete in Turkey: DSI Group at Work on a Bridge Construction Project

The 715km long Black Sea Coast Road is part of the 2nd important connection between Asia and Europe. It leads along the coast of the Black Sea through Turkey and will be one of the relevant parts of the road network connecting Bulgaria, Turkey and the Caucasian countries.

Recently, traffic volumes have increased steadily on this important transit route. Consequently, the Black Sea Coastal Road is now being upgraded to a dual 4 lane carriageway. Highway construction is particularly difficult along the middle and eastern Turkish Black Sea coast because the Black Sea Mountains extend directly to the coast and the whole area is characterized by a steep topographical structure.

A section of the Black Sea Dual Carriageway is being designed as a viaduct in order to avoid the problem of the mountainous topography in this region. DSI Group Headquarter Operations and two DSI licensees, the Turkish company DIVIGER Yapi Teknoloji A.S. and DYWITECH Co. Ltd, are involved in the realization of this project.

The bridge is being built between the city of Giresun and the town of Espiye by the Contractor GÜRIS-METIS JV. When completed, the viaduct with its main span of 165m will be the longest box-section bridge in Turkey. The Viaduct is 330m long and consists of two individual bridges with spans in lengths of 82.5 + 165 + 82.5m each.

The superstructure of each bridge, constructed using the free cantilever method, consists of two 330m long hollow box girders each supported by two piers. Both bridge decks are approximately 14.5m wide, and the superstructure of each bridge weighs 12,000t.

The maximum section depth of the single-cell box girder superstructures is 8.25m at the pier table and decreases to 3.5m at mid-span.

Two pairs of newly developed form travelers are used to construct both parallel box girders simultaneously. The form travelers were produced by DYWITECH and installed and operated by DIVIGER. The form travelers are designed for a maximum concreting length of 5m per segment.

DSI Group Headquarter Operations supplied a total of 744 ETA conform DYWIDAG Post Tensioning Tendons type MA 6819 as well as DYWIDAG Post-Tensioning equipment. The Post-Tensioning system is installed, stressed and grouted by DIVIGER.