New West Terminal

The West Terminal serving an annual total of 4–5 million ferry passengers. Constructed by Port of Helsinki Ltd, the total area of the terminal building is 12,700 m2. Sweco’s experts serve as the site’s structural designers and information model specialists.

The frame of the building consists of the terminal facility and two passenger gangways on both sides of the terminal. The load-bearing frame of the terminal building is made of steel composite columns, beams and trusses, staircase towers of pre-cast concrete elements and cast-in-place and concrete element columns, and concrete element beams.

The architecture of the site is of particular importance. It posed challenges in terms of both structural design and manufacturing. The number of visible stiffeners in the terminal is very limited, and the frame utilises perimeter stiffening, which creates additional challenges for joint design. The design of the concrete elements emphasised visual aspects when designing the seam division of the stair towers and walls. Aesthetics played a significant role in all structural solutions at the site.

The geometry of the site posed a set of challenges as well. The shape of the terminal frame is complex, containing double-curved roof surfaces, slanted propeller-like eave and façade surfaces and high glass walls.

In addition to the complex geometry and architecture of the site, the design was also given an extremely tight schedule. The draft design process began in February 2015 with construction following in September. The tight schedule gave importance to close and good co-operation between the different design parties, and a weekly updated information model was an essential part of that.

Information model in extensive use

The new West Terminal utilises information modelling extensively in designing, implementation and manufacturing alike.

Even the early architectural design of the draft phase utilised the information model. As the design solutions progressed into actual implementation planning, the information model was again utilised in the modelling work. The implementation planning information model is used to print out drawings, such as blueprints and cuts, and utilised for 3D visualisations as well.

Information modelling has also played a key role in coordinating plans and designs.

Sweco’s structural designers used the Tekla Structures software in their design work. The entire load-bearing structure was designed through modelling, as were the reinforcements of the cast-in-place footings.  The frame consists of different materials, and its design and detailing have been carried out in different locations simultaneously. Cable shelves and pipes, lighting fixtures and hole reservations in the walls were modelled in the electricity planning phase.

The contractor actively uses a combination model at the work site and utilises the information in daily work. The element suppliers have manufacturing and installation information models at their disposal.

“Information model coordination has played a central role in coordinating designs. The tight design schedule requires constant communication between the designers, and information model coordination meetings must be held on a regular basis. The combination model with its observations has been available for all project parties to use and comment on,” says Antti Hämäläinen of Sweco, who serves as the project’s information model coordinator.

The information model is the key to the best possible outcome

“The information model has been utilised extensively in this project. Despite the highly difficult geometry, the measurements have been accurate and the structural parts have fit into place well,” says Hämäläinen.

The work site has utilised the model in the planning and organisation of its own work as well as the communication between parties.

The information model has proved particularly useful by making it possible to show the internal geometry of the building to other designers. The shape of the site and the connections between facilities became considerably clearer based on the information model, and an increasingly large portion of the design work could be carried out in advance.

Image: PES-Architects