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Subterranean parking lot in the center of Tapiola opens to business

With more than 400,000 cubic meters of space, Tapiola’s central parking lot is a huge parking cavern. It was built as a side-project to the West Metro and designed during the construction works. Nevertheless, the geotechnical works were actually completed ahead of schedule.

Tapiola Park is an attractive, spacious, well-designed and user-friendly parking lot. Photo: Juha Mäkelä.

The opening of Tapiola’s subterranean central parking lot, named Tapiola Park, was celebrated on Saturday, March 19th. Thanks to the opening of Tapiola Park, there are now a total of 2,100 new parking spaces in the center of Tapiola, 1,650 of which are located in the newly opened subterranean parking lot. An estimated 10,000 people attended the opening ceremony, which turned into a festive public event, to admire the new parking lot and to listen to Hevisaurus and Anssi Kela as well as of course Mayor Jukka Mäkelä’s speech.

According to Project Director Antti Mäkinen, Tapiola’s new central parking lot is the largest public subterranean parking lot in Finland to have been built from start to finish in one go. Some areas of the cavern accommodate as many as four levels of parking.

The parking lot can be accessed by elevators from the Ainoa and Heikintori shopping malls and from Espoo Cultural Center. “The decision to provide elevator access from the cultural center was made retrospectively, and the elevator shaft was geotechnically challenging to design. Project Manager Jannis Mikkola’s team from Sito did a great job in this respect as well,” says Antti Mäkinen and adds: “Building the elevators was a good decision, as there are now also plans to open a theater in the Cultural Center.”

Cars can access the subterranean parking lot from the center of a roundabout on Tapiolantie and from Etelätuulentie.

An interesting engineering challenge

Sito’s role in the project consisted of rock and geotechnical engineering, transport and sign planning, and the structural design of the elevator mentioned by Antti Mäkinen.

Antti_541x387Tapiola had been suffering from a shortage of subterranean parking for a long time. Sito was initially hired to design a parking lot underneath the Heikintori shopping mall in 2006. Antti Mäkinen took over the Tapiola development project in January 2009. “The idea at the time was to build a subterranean parking lot with 1,500 parking spaces,” he explains.

The project only really got going when a decision was made to extend the Helsinki Metro to Espoo. The foundation stone of the new center of Tapiola and the Tapionaukio parking lot was laid on September 15th, 2011. The day also marked the 50th anniversary of the completion of the Central Tower, Tapiola’s most famous landmark.

The project was characterized not only by its large scale but also by constant changes and tight schedules.

The subterranean cavern is extremely vast. Tapiola Park’s total area is 83,470 square meters, which is big enough to house Helsinki Olympic Stadium or four Parliament Houses.

Project Director Antti Mäkinen still has more work to do on the development of the center of Tapiola, but at least the issue of parking has now been solved thanks to Tapiola Park.
Photo: Mika Reunanen

Mind-blowing figures

Comparisons are always fun, and Jannis Mikkola listed several examples to illustrate the huge scale of Tapiola Park:

  • jannis_mikkola_600x600The largest rooms could fit a six-story building, and the length of the parking lot equals the distance between the Sähkötalo building in the center of Kamppi and the old bus terminal.
  • If all the rock excavated to build the facility were to be piled up in Helsinki Olympic Stadium, the pile would be 170 meters tall, comfortably more than double the height of the Stadium Tower.
  • Approximately 1,000 cubic meters of rock was excavated per day on average, and on some days the amount was close to 2,000 cubic meters, which equates to four single-family houses per day.
  • Approximately 65,000 truck loads of rock were transported from the site. If the trucks were lined up bumper to bumper, the line would stretch from Helsinki to Oulu.

The project got off to an extremely speedy start, and tenders were invited on the basis of rough sketches. Planning continued throughout the construction phase. “This was design-as-you-go at its best,” Jannis Mikkola says.

A hundred more parking spaces were added by including a public air-raid shelter in the cavern.

The location of the facility also contributed to the challenge. “We were building underneath the center of Tapiola. Excavators had to be extremely careful not to damage any of the buildings,” he adds.

The works progressed side by side with the West Metro project and aboveground construction works. Scheduling and coordinating the building works required careful planning. “We were still blasting away underground while construction works were already going on aboveground,” Jannis Mikkola explains. “Coordinating between the needs of the sites was difficult at times.”

User-friendliness

mikko_vuorinen_600x600Transportation Planner Mikko Vuorinen was responsible for making the gigantic parking lot and access routes as user-friendly as possible – from the perspective of occasional tourists and local commuters and shoppers alike. Esa Hartman from Sito was responsible for planning traffic control and signs.

Tapiola Park also houses bottle banks and a car wash.

The parking lot is also linked to a shared service area for local businesses. The service area includes a waste collection point for Tapiola’s central vacuum waste management system. Thanks to the subterranean location, cars can enter the parking lot and service area from outside the center of Tapiola, which makes it possible to turn the entire center of Tapiola into a car-free zone.

Efficient cooperation

According to Jannis Mikkola, cooperation between the client, the City of Espoo, the engineers and the excavation company Kalliorakennus Oy ran exceptionally smoothly despite all the challenges. “We even managed to develop new practices, such as a benching technique, which allowed us to increase our efficiency and shorten the excavation schedule considerably,” he says.

“The planning process was long, and we had to make educated guesses at the beginning. We had very little information to go on,” says Mikko Vuorinen. “Although there are things that, in hindsight, could have been done better, we can be satisfied with the end result. Functionality was the highest priority in designing Tapiola Park. And the end result is extremely functional indeed.”

Tapiola Park is a property company owned by six other property companies, the City of Espoo and Länsimetro Oy. The biggest shareholder is LähiTapiola. The total investment amounted to approximately EUR 115 million. The lead designer of Tapiola Park was Jukka Hyvämäki from HKP Architects, construction works were the responsibility of Indepro Oy, and the interior was designed by SRV Rakennus Oy. The lead contractor in the Tapionaukio parking lot, which was built earlier and has now been linked to Tapiola Park, was Lemminkäinen Infra Oy, which used the same engineering team’s drawings.

 

Text: Dakota Lavento