Underground Car Park by the River Alster
The Europa Passage in Hamburg is the largest inner-city shopping mall and a major magnet with international flair for shoppers, customers and visitors alike. The arcade, which was designed by the architects Bothe Richter Teherani, is an attractive, weather independent connection between Mönckebergstraße and Jungfernstieg/Ballindamm situated in a first-class Hamburg city location.
In addition to 30,000 square meters of retail space the Europa Passage comprises 34,000 square meters of representative office space. The glass roof rests on steel arches, covers the entire length of the arcade and is an architectural eye-catcher. The six-floor building is as high as the average traditional office buildings in Hamburg and has an underground car park with 700 parking spaces.
The underground car park was built from top to bottom using the so-called cut-and-cover method. At first, the outer shell made of 80 cm thick slotted walls was driven over 35 meters deep into the ground. A frame-shaped concrete floor thus formed the ceiling of the first basement. The soil underneath was then cut and removed through a whole in the concrete frame. Once the first floor was unearthed, the next floor down was unearthed, and so forth. The groundwater level that is only one and a half meters deep due to the vicinity of the river Alster posed a specific problem here. Actually, the outer walls of the lowest floor are exposed to a 20 meter high head of water.
During the construction of the complex underground car park injection tubes were installed in the construction joints and systematically injected with WEBAC PU Injection Resins after the concrete had stopped shrinking. The cracks in the concrete that are inevitable in case of such a large-scale project were also successfully injected and sealed.
In time for the opening of the shopping mall at the beginning of October 2006, all sealing work had been completed so that the underground car park could be used without any restrictions.