Structural Concrete, Vol. 4, no. 4, December 2003
Ductal® Seonyu footbridge
Moulond Behloul, VSL, France
Kicul C. Lee, VSL, France
Seoul Seonyu footbridge links the main town of Seoul to Sunyudo Island in the Han river. The footbridge consists of two steel accesses that will be borne by a Ductal® arch. The span length of the arch is 120 m. The accesses have a bearing situated on the arch extrados, on both sides of its axis. The pedestrians will walk directly on the central part of the arch. The arch has a pi-shaped cross-section, consisting in a transversally ribbed upper slab and two girders. The width of this arch is 4.3 m and its depth 1.3 m. The equivalent quantity of Ductal® is 0.23 m3/m2. Ductal® is an ultra-high-performance concrete reinforced with fibres. The mean compressive strength of Ductal® is 200 MPa. The use of Ductal® for the construction of Seonyu footbridge is a major innovation and an important step in the development of ultra-high-strength concrete in civil engineering construction. The vibration in the footbridge was considered during the preliminary studies. A solution using a tuned mass damper (TMD) was selected and fitted after preliminary vibration tests on the completed footbridge. After installation of the TMD final tests were made to control the actual levels of accelerations.