Terratec MTBM holes through in Ahmedabad7 January 2021
Ahmedabad’s first-ever use of microtunnelling was brought to a successful conclusion when a Terratec microtunnel boring machine (MTBM) broke through in December on a major new sewage tunnel in the Indian city.
Terratec’s MTBM was selected for the project by ITD Cementation India. The existing drainage system struggles with the current demand and from frequent floods. Located in the western part of the city, the new trunk sewer will cover an area from Vadaj Circle to Mahalaxmi Char Rasta – a stretch of around 6.5km – and will convey around 550 million litres of foul water per day. Sewage from existing systems will be diverted into the new line and transported to a treatment plant at Vasna.
Ahmedabad’s geology includes clay, stiff clay and sand. To cater for the different pipe diameters on the project, the MTBM has been designed for DN1400 concrete pipe with the option of a later size increase to DN1600. The machine also features a cone crusher integrated into the cutterhead structure and a Terratec laser guidance system. Completion of the trunk line will take around 24 months.