Ageing infrastructure is a widespread problem across Europe. In Germany, many bridges are coming under pressure as they near the end of their lifespan amid rising traffic volumes. So how do you replace critical infrastructure without impinging on traffic flows? Bridge upgrade and replacement projects can often prove contentious due to the associated transport congestion and resulting journey delays, which can severely impact the health of the local and regional economy.
As part of a pilot project, Arup has developed a new bridge system for Straßenbau Nordrhein-Westfalen, the North Rhine-Westphalian road construction company, that will cut construction time onsite by more than half, down to sixteen weeks from an initial estimate of about twelve months.
The modular bridge system, designed to keep construction-related traffic disruption to a minimum while shaving months off a project timeline, is now being used for the first time to replace two 1960s road bridges near Werne.
70% less construction time onsite
8 month reduction in traffic disturbance
Keeping the network flowing: offsite production minimises traffic disturbance
Both bridges are designed with modular components, which enables the relocation of large parts of the construction process to remote production facilities: since numerous components can be pre-fabricated offsite, construction times onsite are significantly reduced, helping avoid traffic chokeholds.
The new pre-fabricated bridge system is designed so that the existing foundations can remain in the ground reducing the need for lengthy – and potentially costly - demolition and complex earthworks. Overall, construction time onsite will be cut by as much as 70 percent to around sixteen weeks from an original estimate of about twelve months.
3D design helps optimise use of resources
Modular structures require particularly exact design, allowing only for minor adjustments onsite. To address this, Arup has designed a detailed 3D model for the various construction phases reflecting the changing ground conditions and ensuring an efficient and highly precise design execution.
Many of these modules are made of high-performance concrete and pre-cast in a factory. This high-performance material is more stable than conventional concrete, allowing for slimmer bridges and a more sustainable and efficient use of materials overall which will positively impact cost-control during construction.
This new modular bridge system will allow us to relocate some of the bridge construction process from the road to offsite production facilities. Individual components can be digitally designed and subsequently pre-fabricated to exacting standards. The modules can then be quickly assembled onsite, keeping overall construction time and associated traffic disturbance to a minimum. ” Markus Gabler Leader Bridge Design, Arup Germany
Arup’s innovative modular bridge design system was designed to adapt to different bridge designs, both in terms of form as well as in terms of geological factors with a view to rolling out its use to other projects upon successful completion of the trial.
The animation below shows the construction of Arup's modular bridge system in a time-lapse: