A new cross connection for the Schoren tunnel: tendering based directly on the model
After more than 30 years of service, the A1 urban motorway between St. Gallen West and St. Gallen East will be repaired between 2021 and 2026. For the purpose of increasing safety in the Schoren tunnel, a new cross connection will be built. The Federal Roads Office (FEDRO) is using the subproject as a pilot project for building information modelling (BIM). With the support of Basler & Hofmann, the Federal Office ventured its nationwide debut: for the first time, a project subject to public law was tendered directly from the model.
Expertise involvedBIM consultancy , BIM planning , Digital services , Geotechnical engineering , Tunnels
Federal Roads Office (FEDRO), Winterthur branch
Project with model characteristics
The new cross connection – the QV8 – connects the two tubes of the road tunnel and will serve as an additional escape route. Construction will take place via an access shaft. From this shaft, two cross passages will be constructed by means of mining. These will connect to the existing tubes. For FEDRO, QV8 offered an ideal opportunity to carry out another BIM pilot project: the construction site has been localised and almost completely decoupled from operations. In addition, there are only a few interfaces connecting the overall project. FEDRO’s BIM pilot projects to date have concentrated on the planning phase. With QV8, the Federal Office wanted to explore the added value that BIM offers in the tendering process. The aim was to put out to tender 80 per cent of the services from the model directly.
Tendering with a software-neutral platform
With the tendering based on the model, FEDRO made its debut as a public building owner in Switzerland. Today’s common tendering practice is based on 2D plans and extensive specifications. For BIM projects, this means that the models created in the planning phase have to be meticulously broken down into individual service descriptions according to the Catalogue of Standard Building Descriptions (CSBD) for tendering. To be able to tender the QV8 project directly from the model and at the same time in compliance with Swiss public procurement law, Basler & Hofmann has provided a specially developed web-based platform. This has enabled all contractors to create their bids without market-restricting software requirements, print them out and submit them by post. At the heart of the platform is the model. All contractors had access to the lists of construction parts via a selection screen. The costs for the individual construction parts could be entered via a dialogue window. Since this was a BIM pilot project, each construction part was also linked to a service specification in PDF form.
A continuous data flow
The project has shown that model-based tendering in public procurement is already possible today. The project participants benefit from a better understanding of the project, higher transparency and increased process efficiency. This is made possible by a continuous data flow – from planning to tendering to the construction site.
Overall project management and processing across all phases from planning to commissioning. BIM management, coordination and modelling. Assisting the client throughout the two-stage tendering process: handling of the model-based tendering via a web-based platform. Digital site management: construction based on the model without plans, model-based construction progress and documentation of dimensions, invoicing.