Serving as a vital link across the Enguri River to the Black Sea resort town of Anaklia, Georgia, the Anaklia-Ganmukhuri Pedestrian Bridge is considered longest cable-stayed timber bridge in Europe and possibly the world.
Originally conceived as a 500-metre-long steel bridge, cost challenges proved to be prohibitive. Fortunately, a Georgian contractor with a keen interest in timber construction stepped forward and engaged HESS TIMBER of Germany to assist in providing a more economical timber solution.
Fast + Epp GmbH was retained by HESS TIMBER to provide engineering design for all timber components and connections. Working in close collaboration with concept designers at Leonhardt Andrä und Partner, a finite element model was developed for the entire bridge superstructure.
Given the transportation challenges of shipping materials more than 3750 km, shipping fully-assembled trusses or even individual chord elements longer than 13.5 metres was considered out of the question. Early in the design process, the decision was made to prefabricate all timber components and connections in Germany to ensure quality construction and ease of shipping. The patented ‘Hess Limitless’ connection was implemented at all chord splices and involves on-site gluing of conventional finger-jointed chord ends, as well as additional high-grade timber wedges to the top and bottom of the glulam chords.
All other truss connections consisted of standard split plate steel pin connectors augmented with confining bolts. Kerto® floor panels were power nailed to the truss members.
The extensive use of carbon-sequestering wood as a quickly- and naturally-growing product fosters the traditional values of sustainability, while also contributing to the warm ambience of pedestrians’ experience as they cross the bridge. The Georgian client, Caucasus Road Project, was open to utilize wood as main building material, to promote use of local wood. But to foster this mindset among the public CRP required a pilot project to gain confidence in the design and use of wood for large scale projects.
The design team, therefore, used local chestnut for walkway boards and cladding which later changed to polycarbonate. Following completion of Anaklia Bridge, additional bridges with local Chestnut wood have been constructed by the Georgian client. While the original intention was to clad the entire timber structure with chestnut siding, the aesthetic expression of the timber trusses was so compelling that a decision was made to clad the trusses with translucent polycarbonate panels to preserve the warm wood look.
Georgians were very proud to have one of the longest timber bridges in the world as a vital link to the tourist destination of Anaklia, built by their own people --- and a little help from a small Western European erection crew.