Denmark – Construction work for bridges and tunnels, shafts and subways – SST04 - Tunnel og Konstruktioner (1)

The tunnel project is part of the protection of Copenhagen, Frederiksberg, Gentofte and Gladsaxe against flooding in connection with cloudburst events. The cloudburst tunnel functions by, at high water level in the sewer system, as a result of rainfall events in Copenhagen, Gentofte, Gladsaxe and Frederiksberg, water from the sewer system is directed directly to the tunnel. In cases where the allocated water volume does not exceed the tunnel's capacity, the water will be stored in the tunnel. When there is again capacity in the sewer system and at the treatment plant, the stored water, via emptying pumps at the bottom of the shaft at FSK, will be pumped for treatment at the treatment plant Lynetten, through a newly established emptying pipeline. If the rainfall event exceeds the tunnel's capacity, the water is led to Øresund via the outlet structure at FSK (Fiskerihavnen/Skudehavnen). The existing rainwater network is connected to the cloudburst tunnel via constructions under the terrain, the so-called connection structures. One or more connection structures will be established at most of the shafts. At Fiskerihavnen, an outlet structure and a pump station as well as a connection to the existing sewer system at Strandvænget will be established. The pump station consists of an underground technical installation with a smaller building above ground. The 15 different work locations are on drawings and documents most often referred to with 3-letter abbreviations as shown in Table 1. cf. the tender conditions section 1.1 Contract scope. The connection work locations KIA and MGA are also mentioned. The tunnel sections FSK-KAS and KAS-RIA are contiguous and are executed as a tunnel section from FSK to RIA via KAS. Furthermore, tunnelling is carried out at FSK shaft out to Svanemøllen Bugt in which parts of the emptying pipeline are routed; work for establishment and connection of emptying pipeline is carried out in separate enterprise SST37. Overall, 13 shafts are to be executed which are to be connected with approx. 3.2 km segment tunnel and approx. 7 km pipejacking tunnel. Connection structures are to be connected to the shafts and an outlet pipeline is to be established. Further information about the works can be found in the tender material.