Upper Elahera Canal Diversion Tunnel

CRCHI supplied a 7.6 m double-shield TBM for the Upper Elahera Canal Diversion Tunnel, a key section of Sri Lanka's South-to-North water conveyance scheme. The machine completed a continuous advance exceeding 16,000 metres without any intermediate access shaft, setting an overseas record for the longest single advance by a double-shield TBM. Peak performance reached 808 metres in a month, with operational availability sustained consistently above 95%. A dual-support design lets the crew switch between segmental lining and shotcrete within one to two days as ground conditions change along the drive.