Central Library Oodi
The steel structures of the Center Library Oodi are one sample of Normek’s expertise. Project started in the autumn 2009. Large, heavyweight, special-purpose steel elements made the project technically demanding. Particular attention needed be paid to the design, carrying capacity and the integrity of welded joints delivered. With the success of logistics and installation work, the schedule has stayed well in its time. Order were made by YIT Rakennus Oy that already had a long cooperation history with Normek. The project manager is Pasi Parkkinen.
The Central Library Oodi is located in the centre of Helsinki, Töölönlahti. It is one of the biggest brand projects of the Finland’s 100th independence anniversary. The monumental 18,000 square building is due to be finished in 2018 in the late fall, within the budget of 98 million euros. The library is an important infrastructure destination for Helsinki people – which will certainly be noticed among tourists as well. As a specialty, the library offers a cinema, extensive leisure, working and exhibition facilities, a sauna department and a selection of up to 140,000 books.
The Central Library Oodi was the theme of the international design competition “Metropoli’s pulsating heart”, which was won by the Helsinki Architectural Office ALA Oy with its own design proposal named “translation”. What’s special – the façades are only consisting of wood and glass. According to the architect, a 3-storey building with undulating, relaxed-looking style will be an important public entertainment and meeting place for local people. The name of the central library was also resolved as a result of the competition – “Oodi” refers to a lyric poem that describes the style of the building in a word-of-mind.
Normek Oy is responsible for the substructure of steel structures for the building. The project was launched by the main contractor YIT, in the autumn of 2015. The steel frame is particularly challenging in this project as it has to support a large number of very heavy structures. The carrying capacity must be excellent and the weld seams very durable. The body structure resembles a large lattice structure. First, vertical steel beams were erected on which the transverse beams were installed. Steel arcs were welded with numerous repetitions – one seam welding takes up to 2 weeks with two full-time employees working full time. At each seam, a separate support structure is installed to ensure stability. Concrete slabs also supports the steel wires in the lateral direction.
The first inspections of steel frames were already executed at Normek’s factory in Oulu. Physical metering, also called control metering, ensures the compatibility of steel parts. Even the slightest throwing or measuring error will cause trouble during installation process. The quality of the weld seams was verified by ultrasonic measurement. The measurement was operated by Suomen Testauspalvelu Oy.
As the parts weighed more than 85,000 kilograms each – a 350-tonne crane was needed to lift the massive elements into place. Logistics produced challenges due to the massive size and heavy weight of transports. Slow progression and special attention to turnaround required logistical workers professional skills and iron nerves to be cautious. Parts were transported all the way from the Oulu factory to the centre of Helsinki. Deliveries were allowed to enter the construction site only during night time. Employees had to paid special attention to lifting, installation and safety plans due to the enormous weight of the elements. The steel structure of the library building weighs all together 2500 thousand kilograms.
As with other construction projects, the timetable of Oodi was very tight as well. Normek oy has been praised for it’s rapid progress by YIT. At present, about 70% of the installations are ready. The large steel constructions of the library will be completed by 2017 at the end of June.