The performance prediction of a TBM in a complex geology in Istanbul and the comparisons with actual values

Abstract: Uskudar-Umraniye–Cekmekoy-Sancaktepe metro line of 20 km having two tubes is recently commissioned to Doğuş Construction Company by Istanbul Metropolitan Municipality authorities. The geology is complex consisting of sandstone, arcosic sandstone mudstone, siltstone, shale, limestone, andesite, and quartzitic conglomerate. The geologic units are frequently cut by andesite dykes having significantly fractured contact zones. The area is highly populated, and the overburden changes between 10-80 m. Two TBMs having diameters of 6.57 m already used in Kadikoy-Kartal metro tunnels are refurbished for the tunnel excavations. The paper describes briefly the methodology based on the accumulated data from previous experiences for performance prediction of TBM s. The data is analyzed within a research project sponsored by Turkish Scientific and Research Council (TÜBİTAK), project No 112M859.