Building a bridge straight from a digital model: BIM pilot project Balmbrücke Meiringen

Strengthening of the Balm Bridge would not have been sufficient due to inadequate flood defenses. Simultaneously, restrictions for heavy load vehicles were already in place, impacting the neighboring industrial areas. To minimise construction disturbances in the transport network, a temporary bridge was built until the new three-span bridge was finished. Before the demolition started all service lines that were previously running across the bridge were moved to run underneath the river bed. Due to its relatively small size and limited number of third parties involved in the project, this bridge replacement served as an excellent learning opportunity for integrated digital planning and construc-tion with the use of BIM. For all phases from concept design right up to commissioning, the Civil Engineering Department of the Canton of Bern decided to go paperless, i.e. to not use any printed plans, so that they could learn as much as possible about the potential and challenges of all-digital working methods. The findings from the BIM pilot project were then used to help shape the Canton’s BIM strategy.

Straightforward data exchange thanks to openBIM

As a first step, surveying experts from Basler & Hofmann went on-site and prepared a digital model of the terrain which formed the basis for route mapping and modelling of the slightly optimised road layout. The project team from Basler & Hofmann then modelled the new bridge with a length of 65 meters, a main span of 34 meters and an elegantly, curved structure. Different software tools were used for the modelling of the road, bridge and reinforcement. The coordination of the different spe-cialist models was handled via the open file format IFC on a cloud-based collaboration platform. The foreman of the contractor and the site engineer from Basler & Hofmann also had access to this plat-form during the construction process. A quick glance at a tablet was all it took to be able to carry out reinforcement inspections and to remain up to date with the latest progress reports for the project.