The “transparent” street of Küsnacht: BIM pilot project in infrastructure construction.
The municipality of Küsnacht in the canton of Zurich and Werke am Zürichsee AG are aiming to press ahead with digitalisation in the field of infrastructure construction. For its first project, the municipality took on the complete renovation of Eigenheimstrasse. The pilot project was fully planned out using building information modelling (BIM) and included the complete renovation of the road superstructure, the sewer system and the service pipes. Basler & Hofmann designed and modelled the street renewal project and supervised the building contractor’s submission and the construction work.
Expertise involvedRoads and highways
Municipality of Küsnacht, Civil Engineering Department, and Werke am Zürichsee AG
A side street with urban character
Eigenheimstrasse in Küsnacht is a 370-metre-long side street. Although the street is only five metres wide, the complete renovation was anything but a simple undertaking. Measured by the density of the cables underneath the road superstructure, this side street is on a par with many major urban thoroughfares. The cross-section shows pipes for everything from wastewater, rainwater, drinking water and district heating to electricity and gas. This made the street the ideal pilot project to test the application of building information modelling (BIM) in a civil engineering setting.
Development of an extensive knowledge database
Through the use of BIM in road construction and civil engineering, the municipality is aiming to build up a comprehensive knowledge and project database over the long term, which it will be able to use in the maintenance of its infrastructures. While no one currently knows exactly what lies beneath the surface of the road, in future, the municipality would like to keep track of exactly what has been installed where, when and with what level of quality. This should in turn improve the standard of planning and execution. But this isn’t all: the scheme should also optimise infrastructure repair from both an economic and ecological perspective. A substantial quantity of good-quality fine gravel has been built into Küsnacht’s infrastructure network. However, since the municipality does not know exactly where it has been placed or what quality the gravel is, all road construction projects that are currently being put out to tender include the partial or full replacement of the road superstructure. This is very expensive and makes little ecological sense. This is now set to change thanks to the new digital knowledge database.
A digital twin of the street
The complete renovation of Eigenheimstrasse was fully planned in BIM, centrally on a single platform. This meant that all project data was accessible to the client, the planners and the building contractors at all times. Digital tools were also used on the construction site itself: for example, the foreman took measurements from the model using a tachymeter and a tablet. During excavations, the quantity and quality of fine gravel was also recorded digitally. At the end of the project, the client was able to hold a digital twin of the street in their hands – a data set that is extremely valuablefor future repairs.
Overall leadership, planning for all service phases from preliminary to project execution, including execution in Open BIM, laser scanning surveys, support for geological explorations and TV channel recordings, provision of a workshop with all project participants to clarify the requirements, client support throughout the two-stage submission process including preparation of submission documents, provision of client consultation on the procurement of a data platform with a browser-based viewer and visualising the project model using virtual reality.