J Kumar Infraprojects – MEPL JV and client Municipal Corporation of Greater Mumbai (MCGM) are making excellent progress on the Mithi River Water Quality Improvement Project in Mumbai, India, using a Terratec 3.14m diameter EPBM, currently the smallest hard rock EPBM operating in the country.
The machine was launched in December 2022 and has completed 70% of its first 1840m long drive from Dharavi to Kurla Garden. The Mithi River in sewerage zone 3 runs 17.8km through densely populated residential and industrial areas and is designed to improve water quality in Mithi River, the project will curb the pollution load entering the river.
The EPBM is designed to handle various geological conditions along the tunnel alignments consisting of mixed ground and basalt hard rocks and has 25 rings of 17” rear replaceable disc cutters and a high torque, high-speed main drive. It is equipped with a fully active articulation system to accommodate a minimum curve radius of 250m and has a hydraulic main drive due to size constraints and the installation of a full hyperbaric man lock.
Construction is utilising a 4+1 universal type segment design, with mechanically actuated erectors installing reinforced concrete segments, 200mm thick and 1000mm long. Muck removal, segment transport and machine supply will be via rolling stock and battery locomotives.
The machine was previously used on the Mumbai Sewer Disposal Project (MSDP) Stage-II Priority Works in Mumbai, India by Contractor Michigan Engineering Project LTD (MEPL). Upon the completion of the initial project, the machine was refurbished. The upgrades includes a new type of segment feeder and concentrated polymer injection system for water control and spoil conditioning in rock sections. The backup has been reorganised, additional facilities put on the decks and some new features added to improve the machines operation.
Mithi River is an open sewer that flows through densely populated residential and industrial areas of Mumbai. It is also one of the oldest river systems in India. Wastewater and industrial waste were dumped into the Mithi River. The Mithi River Water Quality Improvement Project aims to control the pollution load entering the river.