As of August 2020, we, Soner Temel Mühendislik İnşaat ve Ticaret A.Ş. have reached 43% financial realization in the "NATM Tunnel Excavation Support Works" project within the scope of Başakşehir-Kayaşehir Metro Line Construction and Electromechanical Works, which we have started with subcontract signed on 21.05.2020. Umbrella Arch methode is applied at Kayaşehir 15. Bölge (Toplukonut) Station because of soil consisting of gray sand, clay shale and gray wacke between sandstone layers. Kayaşehir 15.Bölge (Toplu Konut) Station, which is the starting point of our project, consists of platform tunnels with a total length of 540 meters, 2 NATM Shafts, 7 connections tunnels, 2 pedestrain stair tunnels and 2 pilot tunnels. The Umbrella Arch method, which has been applied by Soner Temel Mühendislik for the first time in 2001 in Turkey, in order to provide a solution to the tunnels that cannot be opened with the existing methods on the Şişhane-Taksim Metro line, has become an indispensable method for difficult ground environment