Hamburg main sewer

The Flottbek main sewer in Hamburg was constructed between the years 1910 and 1912 over the course of the area expansion back then. After the sewer had initially been used as a discharge pipe by the sewage treatment plant Stellinger Moor, it is operating as a pure rain discharge today.

On the basis of an inspection over a length of 3,7 km in the year 2016 it was decided that an extended condition assessment would be applied to six bearings with a total length of approx. 550 m. A closer look was given to both a circular profile DN 2750 and a circular profile DN 2550. The cross section of the Flottbek main sewer is designed three-layered with sewer clinkers and holds loads from the up to 8 m high earth covering as well as the street traffic. Due to the big dimensioning of the sewer, as well as the position in the street area and nearby cultivation, the long-term structural stability is of major importance. 

The extended condition assessment included, aside from the inspection of the sewer, also the extraction and examination of drilling cores as well as a close meshed ground analysis. Building of these results, ZPP was able to assess the current structural stability with the help of a numerical model as well as further developing action and redevelopment recommendations for the operator. The main sewer can now be redeveloped economically and goal-oriented, and thus, it can be maintained for the future.

We would like to thank Hamburg Wasser and all other involved parties within the project for the good cooperation.