Nemetschek Structural User Contest 2013

134 X2 Category 2: Civil Structures Introduction The movable road bridge at Gouda is built to cross over the Hollandsche Ijssel. The bridge is a part of the project ‘construction of the south-east ring road”, aimed at achieving a better and easier road to Krimpenerwaard and decreasing the traffic in the centre of Gouda. The bridge is also called the ‘Gouderakse brug’. The bridge has the span of 30 m and is of the drawbridge type. The bridge is powered by two heavy jacks situated under the bridge deck. The bridge is balanced by ballast situated in the back of 2 peak arms, each supported by 1 tower. The bridge deck is hung up on the end of the arms by a tension bar. The arms have the total length of 40 m and are characterised by their peak and sharp forms. The total weight of the bridge is 400 tonnes. That weight is balanced by 480-tonne ballast. The bridge deck is built upside down. A special lifting procedure was foreseen to turn the 230-tonne heavy bridge deck afterwards. Description of technical questions to be resolved with Scia Engineer Scia Engineer was used both for the dimensioning of the bridge in the traffic situation and the erection engineering of the bridge. The complete 3D model was formed with bars, even the orthotropic deck plate, divided into longitudinal and cross girders with an equivalent stiffness and adopted mass. Correct modellisation of the mass was very important because of the balancing of the bridge. From the engineering point of view, this project has several challenges. First, there were the different states of the bridge to be studied. The possibility of creating different states of the bridge in one model was a big advantage towards calculation of the bridge. With the automatic steel code check (EC) of Scia Engineer it was possible to check all members in all states in one calculation model. This gave an important gain in calculation / optimisation of the structure in the different states. Third, the use of graphical sections with different material properties to model the exact weight of the bridge into the different states of the bridge. The input of complex forms for the arms and towers was possible thanks to the use of graphical sections. Fourth, the calculation of eigenvalues / frequencies of the bridge in order to check if there were risks of vibration under wind loads. Fifth, for the erection engineering the different construction stages had to be examined. Description of how our experience with Scia Engineer proved its completeness • Dimensioning a 3D structure in different states. • The possibility of using and combining the results of Scia Engineer in a flexible way. • The use of graphical sections with different section properties. • Stability calculation and second order calculations. • Calculation of eigenvalues. This project proves the great diversity of Scia Engineer in checking the structure and the use of materials. Modules used: • Base • 3D frame • Steel code check (EC) • Stability • Dynamics “Gouderakse Brug” Movable Road Bridge - Krimpenerwaard Gouda, The Netherlands Software: Scia Engineer