Moenchengladbach. The project uses modern sustainable planning and construction methods
The bicycle and pedestrian bridge over Bettrather Strasse is currently still in the planning stage, but in the virtual world the structure is already in place, at least in its basic characteristics. Because the measure is the first infrastructure road construction project in the city, in which all planning services converge on a central digital platform. In this way, a realistic virtual image of the future structure is created even before the groundbreaking ceremony. The administration has now presented the current status of the project to the district council and the relevant specialist commissions.
“We are building the bridge over Bettrather Strasse first virtually and then in real terms,” says city manager and assistant engineer Dr. Gregor Bonin the technical process in a nutshell. This virtual modeling of building data, known in technical jargon as Building Information Modeling (BIM), has so far been mainly used in building construction. In the meantime, however, BIM has also made its way into many other areas of construction. With this method, everyone involved in the construction does not work on individual plans, but together on the same, constantly synchronized virtual model. BIM has many advantages: for example, planning errors can be identified at an early stage or the required materials can be determined with pinpoint accuracy. Even during subsequent maintenance work, it is enough to take a look at the system to get an accurate picture of the components and their interior.
The “digital twin” created when modeling building information also facilitates communication and coordination around a project. Both between the subjects involved and with the public or – as is now the case in committee meetings – with the political decision-makers. They were able to get a first impression of the basic construction of the planned bridge through the presentation of the administration – although specific implementation planning is still pending and the model will change and develop accordingly in the planning process.
Sustainable thanks to recyclable steel and resistant wood
But not only does the design process of the bridge follow the latest standards, the city administration also wants to act forward-looking in the selection of materials and take into account important aspects of sustainability. The construction of the bridge will consist of steel, the production of which initially consumes a lot of energy. In the course of the previous design, however, the construction could already be adapted to require 150 tons less steel. Furthermore, together with the sponsor, it should be examined to what extent steel which is produced with the most modern and climate-friendly processes and which therefore causes lower CO2 emissions can be used.
In life cycle analysis, steel as a building material for the supporting structure generally performs better than reinforced concrete, for example, because it can be reused relatively easily and with high quality. The planners also want to use recycled steel for the Bettrather Bridge itself, for example to equip the railings with a tightly woven steel mesh. And the city also wants to use new materials or processes for the wood building materials used for the benches and handrails. For example, domestic wood can be permanently made more resistant to weathering by so-called “acetylation”, i.e. treatment with an environmentally friendly substance. This means there is no need to use sturdy tropical woods or environmentally questionable wood preservatives. In principle, it is also possible to reuse the wood at a later date.
The construction of the new bridge will connect the central urban development projects. For example, the measure is an important component of the planned supra-regional cycle superhighway from Krefeld to Mönchengladbach and will create an optimal connection for pedestrian and cycle traffic from the old town to the planned priority cycle route along Bettrather Straße and Peter-Nonnenmühlen-Allee. The construction of the new bridge is financed by the Federal Office for Freight Transport, which is why the design plan is currently available for review by the Regional Finance Directorate of North Rhine-Westphalia. Feedback is expected in early 2023. After that, the detailed design can start, which will be the last planning phase before the construction phase. This can probably start in the third or fourth quarter of 2023. Costs are currently estimated at almost five and a half million euros. However, in view of the current price trend and delivery difficulties, neither the exact costs nor the concrete start of the works can be predicted with certainty.
