As the first digital project, the municipality of Küsnacht took on the complete renovation of Eigenheimstrasse. The pilot project was planned entirely with Building Information Modeling (BIM) and included the complete rehabilitation of the road surface as well as the sewage and utility lines.
Project description
The Eigenheimstrasse will be rehabilitated by the end of November 2019.
In the last stage of the overall renewal, the wastewater and service lines as well as the road surface will be renewed. The infrastructure project of the municipality of Küsnacht and "Werke am Zürichsee AG" will cost a total of around four million Swiss francs. The contract portion of the construction work is two and a half million francs.
The Saar government of Eigenheimstrasse it is a more complex infrastructure rehabilitation. Although Eigenheimstrasse is only five meters wide, its cross-section contains everything imaginable such as sewage, rainwater, district heating, electrical and gas lines.
Due to the tight space conditions, in combination with the various requirements, it is therefore the perfect pilot project to test the digitized process.
Right at the beginning of the Eigenheimstrasse pilot project, the municipality of Küsnacht commissioned the engineering firm Basler & Hofmann AG. Their planners had extensive digitization experience in building construction following the expansion of their own office building in Esslingen ZH, which was consistently implemented without paper plans.
Basler & Hofmann had succeeded in bringing "Building Information Modeling" with the BIM-to-Field approach successfully to the construction site.
Special features
On the Eigenheimstrasse construction site, the foreman takes model-based measurements with a total station and tablet instead of marking out the points with a paper plan and meter tape. The additional measuring points and image files to be delivered to the client for the digitized implementation are regulated by a newly created specification.
During the excavation of the trenches for the wastewater and rainwater, for example, the foreman continuously photographs the individual conditions and simultaneously records the points required for the 3D model. The exact location of the pipes and the volume and quality of the backfilled gravel sand are also meticulously recorded and digitally documented.
Finally, a model of the completed structure, the 'digital twin' that represents one-to-one what was built outside, is handed over to the client. The solid model shows where the sewage system is embedded in concrete. The cubatures can be determined exactly and the exact location and material type of the trench fillings are thus known.
Within this framework, an approximate geological length profile is also created. Thanks to this, it is known at the time of the next renewal what the soil is like, how the gravel and rock layers run and at what level the groundwater flows. This and much more information is directly attributed to the individual civil engineering structures in the 3D model.
All project data is stored on Autodesk's "BIM 360" platform, including all supplements, photos, logs and daily reports. These are accessible not only to the designer and contractor, but also to the client.
Various measurements taken during the paving process are also valuable. For this purpose, predefined parameters are required - especially for temperature and degree of compaction. Systematic recordings of the temperature profile during paving and compaction measurements, among other things, allow statements to be made on the paving quality achieved. On Eigenheimstrasse, full transparency will soon also prevail with regard to the layer thicknesses of the superstructure, i.e. of the foundation layer, the base course and the wearing course. Thanks to the 3D scan carried out by WALO, the owner will know the exact thicknesses and heights of the asphalt layers over the entire area after completion of the rehabilitation. This is important in order to be able to mill out the exact thicknesses and heights of the asphalt layers during subsequent rehabilitation in order to produce high-quality recycled pavements.
4D and 5D monitoring is enormously helpful in ensuring that the road construction site is always up to date in terms of costs and deadlines.
Source: Baublatt "Gläserne Baustelle": Küsnacht digitizes its infrastructure.
