In Castrop-Rauxel, near Dortmund, an exceptional pedestrian-cycling bridge is being built. The crossing will be 412 meters long and will cross the Rhine-Herne Canal in a double S shape, rising and falling while also varying in cross-section. Upon completion, it will undoubtedly be an intriguing structure, a new landmark, and a tourist attraction for the region. However, this bold architectural vision posed an interesting and challenging task for the constructors.
At the invitation of the general contractor, MCE GmbH, our office took up the challenge. As a result, a complete workshop design of the steel construction was created, including a 3D model that accurately replicates this unique shape.
Sustainable Mobility and Neighborhood Development
Along with the bridge’s construction, the existing network of bicycle paths will be expanded, and a new connection will be created between the two cities of Castrop-Rauxel and Recklinghausen. In the future, regional bike paths will lead through the new crossing. Thanks to this, not only both cities but also individual districts will be better connected, and urban and rural areas will be more closely linked. The project also promotes sustainable mobility in the region, especially for cyclists.
River Span Assembly
On October 8, 2022, another important milestone in the bridge’s construction was achieved. The “Jump over Emscher” river span was installed. The Rhine-Herne Canal was temporarily closed for navigation. A 300-ton crane floating on a pontoon lifted the bridge section lying on the shore at the pre-assembly site and moved it to the final location, where the installation took several hours. This segment weighs 105 tons and is 65 meters long, connecting both banks of the Rhine-Herne Canal.
Technical Challenges
1) Bridge geometry.
2) Deformation compensation.
• The asymmetrical shape of the main girders, together with the distinctive geometry required the workshop design to consider a different shape from the target one, in order to anticipate the expected torsional deflections from the loads.
• The shape of the assemblies delivered to the site was defined by complex spatial curves which considered main deflections.
3) High level of design detail.
• Detailed information regarding e.g. element’s milling, ultrasound examination, NCfile marking, and welding preparations at the individual part level.
• Precise quantities of welds and optimized welding control plans based on them.
• Almost 44,000 surface treatments in the model.
4) Technical difficulties.
• Tekla Structures is an industry leader in design software for steel structures. Nevertheless, the project has often reached the limits of Tekla’s technical capabilities (v2020), which the Construsoft team has consistently helped to overcome.
The complexity of the goals and tense deadlines required Jakosta to develop its own software from scratch to create complex spatial models in any deformation variant in the Tekla Structures environment utilizing the Tekla Open API.
In addition to the obvious challenge of the complex geometry of the structure and the issue related to generating ready-to-manufacture NC files that consider the camber, we also grappled with its derivative: the client’s requirement to provide precise surface areas for each type of anti-corrosion protection (of which there were several), in a way that enables further accuracy verification of the results.
Estimation was out of the question due to the large number of exceptions and details, and manually drawing them on each of the thousands of 2D plates isn’t our style. Thus, we enlisted Tekla itself and a tool we specifically wrote for this task: the Painter. With it, we managed to “paint” the bridge according to the guidelines. Consequently, from nearly 44,000 painted surfaces, we obtained accurate material breakdowns associated with specific item numbers and easily checkable in the IFC model we exported.
