Grandfather's Bridge - Working Efficiently and Improving Quality with BIM
The Grandfather´s Bridge is a full-blown BIM project from call for bids to public opening and beyond.
The Grandfather´s Bridge project, striving to achieve paperless design and construction, created new practices for transferring BIM data from one project party to another. Utilizing modeling in the planning phase ensured that errors would be avoided and made the transfer of information faster and clearer. For the project parties, this created significant savings in time and other resources.
Smooth start to BIM
The general contractor, Kreate, was fairly new to utilizing BIM when they began the project, but using Tekla software in a BIM project easy was easy for them. Aki Kopra, Project Engineer at Kreate, explained that Building Information Modeling was used all the way from the bidding phase to project delivery.
“In the bidding phase of this project, the Building Information Model was an official and binding document. I think that this type of method is becoming more common, but for me, this was the first project in which we had a fixed model to support our estimation calculation during the bidding phase,” Aki Kopra says.
Creating shared understanding
In the Grandfather’s Bridge project, BIM was not used only for design but also for setting up schedules as well as monitoring and supporting the fabrication and erection of various structures. The steel structures, for example, were given three different statuses to schedule – design, fabrication and installation. Concrete pours were also scheduled in the model.
The model was used for visualizing the various phases of the project for the client. For the workshop that manufactured the steel structures, it enabled scheduling and fluent collaboration between the site and fabrication operations. Kopra stresses that visualizing the structure in 3D with the Tekla model was a significant help in processing the information like managing site operations. The bridge’s planning process was streamlined and avoiding errors resulted in time savings.
“The planning process is easier and clearer with BIM. It also provides more transparency for all the different parties of the project. BIM allowed the site crew to see and understand the structure of the bridge. This makes planning work, as well as the entire project, more fluent, quicker and flawless,” says Jarkko Savolainen, building information specialist at A-Insinöörit Oy, the BIM consultants of the project. The project parties chose Tekla Model Sharing to access the combined model. As a result, the model stayed always up to date and all team members got the information they needed.
Fabrication, Procurement and Delivery
The project utilized BIM for manufacturing different structures. The challenging steel structures were modeled as workshop models, which were then used for fabrication purposes. After the temporary steel structures were removed, the steel structure took its final shape as designed by the architect. The steel superstructure was successfully fitted to the concrete abutments erected earlier.
Using BIM, the reinforcement was designed correctly from the beginning, and the overall coordination of the installation in the construction phase was especially smooth. Aki Kopra says that the procurement and delivery of materials proved to be more efficient with the Building Information Models as the reinforcement for certain parts of the bridge could be delivered reliably on time to the construction site
“With the schedule, timing the deliveries correctly has been easy. The site is never on hold due to a lack of material, but instead the work continues without delays. In addition, punctual deliveries and logistics are a great help on a site where space is limited,” Kopra sums up the benefits of BIM during the construction phase.
Model information also benefits the client and owner of the bridge, the City of Helsinki. Ville Alajoki, Senior Project Manager at the Public Works Department of the City of Helsinki, considers the project extremely successful. ”Building Information Modeling allows us to improve the efficiency of construction,” says Alajoki.
“Everything in the project was done correctly from the very beginning, in other words, faults were anticipated, and, thus, no extra repair rounds were necessary. I believe that new technology enables new innovations, and efficiency will further be improved in many areas in construction such as producing reinforcement elements off-site.”
Grandfather's Bridge in figures
- Location: Helsinki, capital of Finland
- Longest span: 144.3 meters
- Bridge width: 4 meters
- Shape of the bridge: The bridge widens at the other end, where the traffic lanes branch into two directions
- Height under bridge: 4.7 meters
- Cover structure: all steel
- Bridge deck: Hung with 22 tension-rod pairs
- Deck’s installation blocks: Welded together on site