Cologne, Germany – After demolition of the existing building, a new administration building will be constructed on Otto square in Cologne’s Deutz district to house the central administration of the “Landschaftsverband Rheinland” association (LVR) on a total area of 7,357 m 2 . BAUER Spezialtiefbau GmbH was engaged by the LVR with construction of the excavation pit.
Work includes the construction of an excavation pit up to 8 m deep comprising a contiguous pile wall with wood and shotcrete paneling in the north as well as a secant pile wall in the west. In the east and south, the encompassment of the excavation pit is provided by existing walls of the underground garage. The retaining structure works are being carried out at the same time as demolition of the existing building.
The secant pile wall is being constructed on the temporarily supported ceilings of the basement floors. The piles have a diameter of 750 mm and 880 mm. “The tie back work, including walings for existing walls of the underground garage, is very labor- intensive. And archaeological digs in the course of excavation work in the northern area of the excavation are also anticipated,” says Bauer Project Manager Andreas Hertenberger. Further, the underground garage walls are underpinned with DSV bodies. In the southwest area of the excavation pit, pipe bracing with lengths of up to 30 m are installed. Bauer’s tasks also include the construction of wells and the dewatering system. For the latter, an approximately 500 m long drainage pipe to the Rhein river was installed that transports water at a rate of 4,800 m³/h.
A BAUER BG 24 H is in use as well as a KLEMM KR 704, KR 702 and a KR 806 rig for the anchor drilling work. Work began in early April this year and the completion of the entire new building, with a height of 69.5 m and 17 stories, 182 parking spaces for cars and 208 parking spaces for bicycles, is planned for August 2022.