"Uskudar - Umraniye - Cekmekoy" Metro Line is a fully underground project connecting the Railway Bosphorus Tube Crossing and the Umraniye and Cekmekoy districts located in the eastern outskirts of Istanbul, running in a very dense urban area, below buildings and sensitive structures. The project includes the TBM and NATM excavation of 16.7 km long main line composed by two single-track tunnels, 16 underground stations (mostly by NATM), depot connection tunnel, depot and maintenance area buildings. Kisikli Station is an example of a large cavern with a 210 m2 excavated area (20 m width and 13 m height). The station connects with the tunnels via a centered elliptical vertical shaft and an inclined gallery for escalators.
Tunnelconsult has been in charge of the structural final design including the GBR, TBM segmental lining, Conventional Tunnels support & final lining and emergency cross-passages. During works, ground treatments, settlement studies and monitoring plan have also been defined.
The Kargi project was developed by the Electricity Projects Research Administration (EİE) General Directorate for the purpose of utilizing the energy potential in the available head in the section of Kizilirmak between Osmancik town and Boyabat reservoir. Main elements include a 11.7 km long headrace tunnel excavated in medium to very poor quality rock masses of the Kunduz metamorphic formation and Kirabaşi complex. This long tunnel has been excavated with a Double Shield TBM installing a rectangular - trapezoidal segmental lining with 8,7 m i.d. and 40 cm thick segments. Due to space and access constraints, the TBM was launched from a temporary adit and extracted at a 15 m x 16 m square cavern (about 130 m2 area) as shown.
Tunnelconsult made the detailed design of the TBM dismantling cavern and its lining support.
The "Zapote-Curridibat" urban tunnel connect "Florencio del Castillo" highway to the San José ring road. The proposed solution foresees a 2500 m long twin tunnels, excavated by NATM method through "lahar" volcanic soft-rocks. Each tunnel contain three lanes designed for heavy truck traffic. The proposed section is poli-centrical, composed by several tangent circles, having a carriage way width of 12,5m and a vertical clearance of 5,1 m, resulting in excavation section of 148 m2.
Tunnelconsult participated in the feasibility studies providing its expertise for recommendations on tunnel requirements and installations, definition of the most suitable tunnelling methodology, recommendations on temporary and final lining, risk analysis and time/costs estimation, and analysis of expected settlements and monitoring requirements.