By rosebell
Excavation of the Priority Sewer Tunnel 1 (PST-1) has been completed by a Terratec 3.85m-diameter rock slurry TBM, whereas this machine has been advancing steadily on the PST-1 alignment since achieving its first breakthrough in Malad West. In order to finishing the remaining section of the tunnel, currently the tunneling machine is being prepared for its final 1.2km drive, while almost 4.5km of tunneling has been completed.
Including the construction of a 3,200mm finished internal diameter sewer tunnel with a total length of around 5.8km beneath densely developed areas of Mumbai, this project is overseen by the Brihanmumbai Municipal Corporation. With the aim of ensuring safe construction with minimal surface impact, careful control of excavation and ground behaviour is required because the alignment runs below busy road networks and existing residential and commercial developments.
Considering that the tunneling is being carried out under challenging urban conditions, including close proximity to existing structures, buried utilities and environmentally sensitive areas, comprehensive monitoring of tunnel alignment and ground movement has been implemented throughout excavation to minimise surface settlements and protect surrounding infrastructure.
As a critical part of Mumbai’s wastewater management system, the sewer tunnel is due to convey sewage to downstream treatment facilities and marine outfalls after completion. The project is going to significantly decrease the discharge of untreated wastewater into local waterways and the Arabian Sea.
