ABSTRACT
At 7am, on March 03, 2018, one of two TERRATEC 6.56 m diameter Earth Pressure Balance Machines (EPBMs) being used by the Şenbay Madencilik-Kolin-Kalyon JV on the new Dudullu-Bostancı Metro Line, in Istanbul, Turkey, completed an outstanding advance of 26.6 m (19 rings) in just 12-hours. The TBM and its crew worked non-stop – alternating between 20-minute mining and ring building cycles – throughout the night shift to accomplish a new production record for a TBM of this size and class in Turkey. The 14.2 km-long Dudullu-Bostancı Line runs north to south under the densely-populated Anatolian side of Istanbul and is located entirely underground at an average depth of about 30 m. Achieving consistently good TBM production rates in this dense urban environment – with limited space on a busy open-cut station site – is a testament to the importance of teamwork and well-planned logistics, and ultimately led to the early completion of tunnelling on an extremely challenging contract schedule.
