Technically demanding car park Airutparkki to be built in Jätkäsaari

The 4900 square meter car park Airutparkki will be built to the new residential area Jätkäsaari in southern Helsinki. Vahanen executes the structural and HVAC engineering of the project and Innovarch Architects is responsible for the principal and architectural design.

Airutparkki is a one-storey, subterranean car park facility which upon completion will serve the residents of block 20801. The solution is based on using the driveway of a rock space complex as an entry route and utilizing the landfill volumes of Hyväntoivonpuisto Park as a space. Thus the parking spaces can be realized above the flooding level without them breaking the semi-public inner courtyard entity of the buildings and without them being visible in the city space.

The project’s methods for foundation and construction are demanding, as it joins the tunnel structure below, Hyväntoivonpuisto Park above and it is limited by surrounding residential buildings, which are constructed partly on top of the car park’s exit ramp. The ground conditions are also very challenging as the foundation methods vary significantly. The superstructure was decided to be executed as a post-tensioned concrete structure due to the high volumes of landmass carried by it.

– Building information modelling (BIM) has enabled us to locate critical points in the structural design, as the construction space is very limited due to the surrounding buildings and the tunnel below. Also the post-tensioned concrete structure has brought additional challenges to the design process, says Heikki Kivinen, structural engineer for the project from Vahanen Group .

The nowadays more common BIM has been found very useful particularly in these types of projects, as it enables the surrounding factors to be taken into consideration more tangibly already in the first phases of the design. The rock car park ROKKIJÄTKÄ associated to this project has also been designed with BIM by Innovarch Architects. Thus putting together multiform geometrics and needs for space was possible by utilizing a common review model already in the project’s preliminary drawing phase in 2012.

The location of Airutparkki has brought along not just physical challenges but also a bunch of contractual demands, in addition to requiring an extensive and long authoritative process. However, this all has enabled the residential block to be realized so that it respects the original architecture competition winner’s basic idea of semi-public courtyards.

The execution phase’s structural design began a few months ago and will be completed during summer 2014. The excavation work should commence in Jätkäsaari in August. The main contractor for the project is SRV and geotechnical design is conducted by Sito.