Stormwater Discharge Pipeline for Europe’s Longest Tunnel

Due to the project’s spread over a large area, lots of old pipelines had to be redirected and new lines installed, one of which conveys stormwater to the Vltava River. Since the new underground road was built in the vicinity of the old concrete line DN 2000, a temporary 30 m stormwater discharge was set up and fixed on supports on a make-shift bridge before construction works commenced. 5.85 m long HOBAS CC-GRP Pipes were used for this purpose. Rubber strips inserted between the steel supports and the couplings as well as rubber lined steel belts restraining the pipes were utilized to protect the pipeline material. Since low temperatures are expected for the winter months, the line was equipped with heating wire and thoroughly insulated. The remaining pipe section between the bridge and the old sewer was laid in a trench. After completion of the tunnel’s top, the HOBAS Pipes DN 1600 were installed on the former route of the stormwater line. The pipes were encased in concrete on a surface of 180 degrees for there was no possibility to backfill the pipe zone and trench.