France-based tunnel boring machine (TBM) manufacturer Terratec has announced that two new earth pressure balance machines have just achieved site acceptance testing for Istanbul’s metro project in Turkey.
The new TBMs bring the number of Terratec machines working on the project to seven and the latest two will be used by the Gulermak, Nurol and Makyol joint venture on the Ümraniye-Ataşehir-Göztepe Metro line.
The Ümraniye-Ataşehir-Göztepe project is one of five new metro lines currently being built by the Istanbul Metropolitan Municipality and the five new lines will expand the network from 145km to 480km.
The 13 km long Ümraniye-Ataşehir-Göztepe Metro line will feature 11 stations be built primarily by TBM sprayed concrete lined connections to form a second north south corridor at 30m below the Anatolian side of the city.
According to Terratec, its mixed-face dome-style cutterheads with an opening ratio of about 35% that have proven to work extremely effectively in Istanbul’s mixed geology, which includes low-strength sandstones, siltstones, limestones and shales.
The new TBMS will be launched from Finans Merkezi Station and mine towards Göztepe Station and work 24 hours a day.