WorldWide Drilling Resource

Specialist Foundation Engineering for Düsseldorf’s Tallest Residential Tower Adapted from Information by BAUER Group With a population of about 617,000, the North Rhine-Westphalian capital Düsseldorf is the seventh largest city in Germany. To meet the growing demand for living space, the UpperNord Tower, a modern residential development, is currently being built. Located at the northern entrance to the city, the 390-foot-high residential tower will be the tallest of its kind in Düsseldorf. The UpperNord Tower will have 36 floors, with the majority of the space being used for 432 planned residential units. It will also include a variety of restaurants on the ground floor, a three-story underground parking garage, and a five- story hotel, which will adjoin the building. The client, UpperNord Tower GmbH & Co. KG, a member of CG Group AG, con- tracted the joint venture, which consists of BAUER Spezialtiefbau GmbH and Gerhard Kliemt GmbH, to carry out a variety of specialist foundation engineering and earth works, as well as construct the dewatering system for the impermeable retaining structure of the UpperNord Tower. Around 19,600 square feet of shoring wall for the retaining structure was constructed using the low-vibration mixed-in- place (MIP) method, which involves mixing the existing soil in-situ with a binding agent. A triple continuous flight auger was used to produce a homogeneous soil concrete. By using the embedded soil as a building material, there are economic and ecological advantages over conventional shoring, and resources are conserved. One challenge for the project was drilling to depths of nearly 80 feet, but such depths wouldn’t have even been possible with the MIP equipment from several years ago. An RG 25 S from RTG Rammtechnik GmbH, a subsidiary of BAUER Maschinen GmbH, was used for the MIP work. In addition, an RG 16 was used to install 700 tons of reinforcement in the form of inserted double steel beams. This reinforcement is another special feature of the construction project. To secure this impressive excavation, additional anchors with three to six strands were installed. A KR 806 from KLEMM Bohrtechnik GmbH was used in the anchoring work. A second layer of ground anchors were constructed to protect against pressurized groundwater; however, some of the anchors will have to be removed because of conditions imposed by the city of Düsseldorf. The project also included the scheduled removal of obstacles using a BAUER BG 40, dewatering for nine months, as well as excavation and disposal of soil. The specialist foundation engineering and earth works project began in December 2018, and was expected to be completed by the end of June this year. 7 WorldWide Drilling Resource ® AUGUST 2019 C&G