1915Çanakkale Bridge, Turkey: challenges and achievements of deck erection over the Dardanelles

Abstract

The 1915 Çanakkale Bridge spans the Dardanelles at the western end of the Sea of Marmara. Part of the Kınalı-Balıkesir Motorway in the northwest of Turkey, it is the longest suspension bridge in the world. The 2023 m long main span leaves a 1600 m x 70 m navigation channel. Two 318 m steel towers support the main suspension cables at 38 m separation. The deck comprises a pair of 14.5 m wide, 3.5 m deep aerofoil steel box girders connected at intervals by transverse box girders. Eight 450 t capacity lifting gantries were required for deck erection, two for each side span and four for the main span. There were 153 deck segments to be erected, of which 143 were erected with the gantries. The gantries were self-erected onto the main cables. Environmental conditions and maritime traffic in the strait were key factors in the development and choice of construction methods for the bridge. This paper describes deck erection with the lifting gantries and focuses on the development, design, testing and operation of the self-erection system; an innovative solution which maximises pre-assembly off the critical path, minimises disruption to shipping and allows installation of the gantries without floating cranes.