Effect of changing methodology of tunnel final lining on the construction duration of a metro project

Abstract

Uskudar-Umraniye-Cekmekoy Metro Line (UUCM) is the second metro project located at the Asian side of Istanbul. In this paper, effect of changing construction methodology of final lining of tunnels on construction duration and cost of Cakmak Metro Station is analyzed. Concourse of Cakmak Station was built by cut and cover method. The rest of the station was tunnel and built by NATM. Conventional cast concrete was used for the final lining of tunnels. Changing the final lining (second-ary lining) of all tunnels in Cakmak Station from conventional cast concrete to sprayed concrete (shotcrete) is examined, since it was a very critical station in the middle of metro line. Based on our analysis, using shotcrete as final lining of tunnel instead of conventional cast concrete could give the opportunity to complete the Cakmak Station about 6 months earlier and with 15 % less cost. © 2019 Taylor & Francis Group, London.