Terratec is the sole supplier for the project’s segmental tunnels, providing two TBMs. J Kumar and Michigan Engineers Private Ltd (MEPL) Joint Venture will use the rock slurry TBM and a rock EBPM to build the 5.8km Mumbai Priority Sewer Tunnel (PST-1) and the 4.7km Priority Sewer Tunnel (PST-2).
The new sewer network, being constructed for Brihanmumbai Municipal Corporation, will improve wastewater collection, treatment and disposal processes, and reduce the environmental impact of wastewater. It will also help improve water quality in Mumbai's Mithi and Oshiwara rivers.
The rock slurry TBM is designed to handle various geological conditions along the tunnel alignments consisting of weathered/fresh breccia and basalt. The TBM has 23 rings of 15in replaceable disc cutters and a high-speed main drive capable of turning the cutterhead at up to eight revolutions per minute. The TBM has an active articulation system to accommodate a minimum curve radius of 250mR. The main drive is hydraulic because of size constraints and the installation of a shield integrated man lock.
The TBM is using 5+1 universal type segment design with reinforced concrete segments 200mm thick and 1200mm wide.
Slurry removal and treatment is via the Terratec slurry transportation system and slurry treatment plant.
The MSDP – Stage II Priority Works consist of several sections, including branch tunnels to pumping stations.
