By rosebell
The tunnel drive for Stockholm’s new power tunnel has been completed.
Following excavating the Anneberg-Skanstull,TBM Elektra, operated by the Hochtief-Implenia joint venture, broke through on May 3 and this Herrenknecht open gripper machine dug through hard rock 50-100m beneath the Swedish capital.
Linking substations at Anneberg and Skanstull, this 13.5km tunnel is the second of four phases in Svenska Kraftnät’s (Swedish National Grid) City Link project. Additionally, the project includes six ventilation shafts, elevator systems, the construction of technical buildings for electrical equipment at Anneberg and the shafts across the city.
Considering that the geology of the this 5m-diameter tunnel’s path involved extremely hard rock, a large volume of injected grout material was required and the tunneling team also had to work under densely populated areas of Stockholm and in the immediate vicinity of the Strömmen passage (part of the Baltic Sea) as well as several historic and sensitive buildings such as the University of Stockholm, museums and galleries.
According to Implenia’s head division civil engineering, Erwin Scherer: “I am very proud of the experienced team, which applied their comprehensive tunnelling experience and showed great commitment to the project.I thank everyone for their excellent work and our client Svenska Kraftnät for their collaboration and trust.”
