NCT Phase 1, Nairobi, Kenya

Northern Collector Tunnel Phase 1 – Water Tranfer Tunnel: Main Tunnel, Irati Intake Drop Shaft and Irati Adit Tunnel, Gikigie and Kaanja Intersection Chambers and Portals (Maragua, Gikigie, Kaanja & Githika) Primary Support and Final Lining Reinforcement Design

Project Components: a) Main Tunnel: an 11775m long NATM Tunnel, of 3.2m nominal section diameter, with 50~200m overburden. b) Irati Drop Shaft & Adit: a 52m deep drop shaft of 4m nominal section diameter connected to the Main Tunnel via a 13m long Adit Tunnel of 3m nominal diamter. c) Gikigie and Kaanja Intersection Chambers and Adits: Intersection Chambers of the Main Tunnels and the Adits, of 10.6m length, 8.5m nominal section diameter and 50~75m overburden. d) Maragua, Gikigie, Kaanaja and Githika Portals Studies: Geotechnical Evaluation and Geotechnical Design of Underground Excavation and Primary Support for a,b, c, d, Geotechnical Design of Retaining Structures (Pilewalls) at Maragua Portal.