Tendons Strengthen Bridge at Lake Woerthersee
The southern A 2 Motorway leads from Vienna to Italy and is Austria’s longest motorway. Near Lake Woerthersee, a comprehensive rehabilitation of the southern motorway (km 346.30 - km 345.90) was carried out at the Velden West interchange in 2014. This project also included the repair of the V12-2A and V12-2B bridge structures.
DYWIDAG produced and supplied external tendons that were installed longitudinally along the webs of these hollow box girder structures. The prefabricated Type 66 Wire EX Tendons in lengths of up to 245m run on both sides of the hollow box girder without any couplers. Due to the fact that the external tendons were completely prefabricated and that no couplers were used, the installation of the tendons was carried out very quickly. This type of external tendon does not require the assembly of tendons that would have been necessary when using single strands nor the cutting of the excess lengths at the anchorages after finishing the stressing operation.
In order to effectively counteract dead weight and traffic loads, the tendons were deviated where necessary by deviation saddles. The bridge features a curved geometry, resulting in inclined diversion planes at the deflection points and supports. This would have resulted in a very complex production of conventional deviation saddles consisting of pre-bent steel tubes or steel boxes. In this project, however, the problem was avoided thanks to DSI’s standard plastic deflection half shells, which can be simply placed into straight steel tubes and slightly turned inside the steel tube whenever and wherever necessary.
To stress the external tendons, DSI supplied a Hollow Piston CFRP Cylinder that ensured a quick and easy stressing process due to its extremely low weight.