Development of industrial estate, Borgstedt

At the beginning of 2022, Tiefbau Hamburg was awarded the contract for the development of a new commercial area of around 40 hectares, including the final expansion. The main construction work included approx. 85,000 m³ of earthworks and the construction of two rainwater retention basins to ensure buoyancy safety. This required soil excavation with a volume of approx. 65,000 m³ and the construction of a 13,500 m² geomembrane.

In addition to the construction of approx. 2,000 m of rainwater sewer and approx. 950 m of wastewater sewer as a gravity sewer in open trench construction, a further approx. 800 m of wastewater pressure pipe was installed as a horizontal directional drilling. Part of the construction work was also the construction of rainwater clarifiers incl. corresponding tee structures and a wastewater pump shaft with MID shaft for flow rate measurement.

As part of the surface construction, stone setting work was carried out on an area of approx. 6,500 m² of paving and approx. 5,000 m of kerbs as well as asphalt paving including cycle path asphalting on an area of approx. 20,000 m². To connect the new industrial estate, the traffic situation along the main road was changed. A new junction with traffic lights and a counting station was built here.

The very heterogeneous soil conditions with partly cohesive soils with a tendency to flow posed particular challenges. Against this background, the geometry of the rainwater retention basins had to be fundamentally redesigned during construction in order to achieve the necessary lowering of the groundwater level.