Green frame Bochum

Part of Bochum’s inner city drainage system is to be rerouted in the near future and discharged into the Marbach, which is already overloaded at present. In order to control the quantities of water discharged, a higher-level stormwater retention channel with downstream stormwater retention basins is being built on the former heavy industry site “Untere Stahlindustrie”. A green corridor and part of the new high-speed cycle path (RS1), which were not part of our brief, are being built on the same site.

The construction area posed a particular challenge in this project. Due to the former heavy industry, the entire project area had to be treated as a contaminated area with a remediation plan, expert monitoring and black and white areas. In addition, the massive, underground reinforced concrete foundations of the former ThyssenKrupp plant meant that no explosive ordnance clearance could be granted in advance. These boundary conditions posed a great challenge to our employees in terms of coordination and process planning, but also to the construction technology, which was in the best of hands with Depenbrock.
The entire construction site was initially demolished to a depth of 5m and the resulting reinforced concrete demolition was broken up on site using a crushing plant. The crushed material was reinstalled together with the remaining, less contaminated excavated material in a former track cut.

In the course of the sewer construction work, dimensions ranging from DN 800 to DN 1,800 were installed over long stretches, including a new sewer pipe. Prefabricated distribution structures and lamella clarifiers. The downstream rainwater retention basin had to be partially excavated and profiled using a long front excavator with a 21m reach due to the large slope lengths. The GPS technology in our devices was of great benefit here. The outlet and overflow structures with a max. Individual weight of 55.7 tons. were built using 400to. The pool sides were sealed with clay sealing sheets. The measure is completed by the preparatory soil profiling for the subsequent green corridor and cycle highway.