RBO, Hamburg

Between Hamburg's Elbe River and the city centre,PORR Spezialtiefbau Region Nord is constructing as part of a consortium an an approximately 14,200m² watertight, two-part construction pit. This will form the foundation of what is currently one of the largest new-build projects in the city: the construction of around 1,000 apartments in the Rothenburgsort district, due to be completed by 2025. The clients and employers are the construction project developers Instone Real Estate, evoreal GmbH and the SAGA group of companies. 

Specialist civil engineering methods intelligently combined to overcome complex construction challenge 

The specialist civil engineering services for this major new-build project are on an exceptional scale: 10,620m² of sealing wall, 1,845m² of diaphragm wall, 14,200m² of soft gel sealing base, 3,320m of temporary strand anchors and 1,214 Atlas full displacement piles will be installed for the construction pit. These procedures need to be intelligently combined to overcome the complex construction challenge. The sealing walls and cast-in-place concrete diaphragm walls in the first section for evoreal have already been produced. Explosive ordnance detection for client evoreal has also been completed. The sealing base was produced using the injection method with soft gel. 

Particular challenges the work entails include the construction of a continuous soft gel base of the size specified and the simultaneous production of the retaining walls and floor to a tight schedule. Due to the interaction between retaining wall, floor, deep foundation and dewatering, close collaboration and precise coordination is required among all those involved in the project. On top of this there are massive unidentified existing building structures in the subsoil, placing increased demands on the team when it comes to production and installation of the soft gel base.

With its high level of expertise, years of experience, strong team spirit and the support of its sister company PORR Equipment Service, which is providing the necessary special equipment, the team overcomes the challenges faced. 

One-stop shop: construction pit as an all-in-one solution 

The specialist civil engineering experts were able to win the employer over with an economic solution: a construction pit as an all-in-one solution from a single provider. Adherence to schedule is also key to the project. Together with consortium partner E.K.W. Erd- und Straßenbau, which is responsible for the extensive earthworks, the team is providing an economic solution to meet the requirements. Subsidiary PORR Spezialtiefbau Planung will carry out the execution planning, ensuring that it qualifies for approval. 

An eye to sustainability: efficient energy management on the construction site 

In the interests of environmental protection, PORR is particularly focusing on recording energy consumption on the construction site in Hamburg-Rothenburgsort. The aim is to identify potential energy wastage and implement suitable measures to prevent it. A digital electricity meter has been installed for the purpose. Consumption will be calculated automatically on a daily basis and compared with daily output. The Hamburg construction pit is one of three pilot construction sites where energy consumption is being closely tracked.  

www.evoreal.de