The Troja Bridge with Macalloy 520 tension rods system
The Troja Bridge is the latest addition to the Prague ring road and will carry a dual carriageway, two tram lines and pedestrian and cycle paths over the river Vltava.
The unique criss cross formation of the hangers makes the bridge stiffer, and allows for greater length to height ratios to be achieved over standard bowstring arch bridges.
The bridge has a span of 200 metres while the arch is only 20 metres high at its highest point compared to a standard bowstring arch which would need to be 50 metres tall. This arch bridge design helped save up to 40% in material.
Macalloy supplied its 520 tension rods system to be used as the bridge hangers. Macalloy designed a unique fatigue resistant thread form for the project which was tested in accordance with EN 1993-1-11:2006 and meets the requirements of Eurocode 3 for fatigue connections in bridges.
The steel tension rods were tensioned using Macalloys Techno-Tensioner device – a device that enables on-site stressing of tension rods using a turnbuckle connection.