By Lynda Myer
As the sole supplier for the project’s segmental tunnels, Terratec has commissioned its rock slurry TBM on the Mumbai Sewer Disposal Project (MSDP) Stage II (PST1), while this company also is providing two other TBMs for this project.In order to constructing the 5.8km Mumbai Priority Sewer Tunnel (PST-1) as well as the 4.7km Priority Sewer Tunnel (PST-2) respectively, J Kumar and Michigan Engineers Private Ltd (MEPL) Joint Venture is going to use the rock slurry TBM and a rock EBPM.
The station of launching this rock slurry TBM with 3.85m diameter was the Malad Shaft S07 Pumping Station, whereas it is due to dig through a range of geology, including weather/fresh breccia and basalt, and following encountering fresh rock it will achieve a daily excavation rate of up to 14 rings.
A slurry system controlling excavation face pressure, 23 38cm replaceable disc cutters, a high-speed main drive capable of 8rpm, and an active articulation system accommodating a minimum curve radius of 250mR. are the contents of this TBM and its hydraulic main drive includes a shield integrated man lock.
The TBM employs a 5+1 universal type segment design, featuring reinforced concrete segments 200mm thick and 1200mm wide. The Terratec Slurry Transportation System and Slurry Treatment Plant are used for slurry removal and treatment.
Considering that an effective slurry removal is nesseccary, this system uses a centrifugal slurry pump, while mud treatment technology and a remote-control maintenance system is the method that the Slurry Treatment Plant uses. This is a effective combination for efficient excavation over long distances and also is cost-effective throughout the process, as Terratec says.
As the Stage II Priority Works, the MSDP project comprises of a sewer tunnel to the existing Malad Pumping Station. Additionally, another branch sewer tunnel links from the Gorai Pumping Station, and a tunnel stretches from the existing Malad Pumping Station to the proposed Malad IPS at Malad WwTF. This project involves constructing shafts and upstream connections to reduce wastewater flow into existing collector sewers and decommissioned pumping stations.
The advantages of this project will be developing sewage collection networks, providing new pumping stations, wastewater treatment facilities and treated effluent disposal systems. The daily performance of these treatment plants in recycling is estimated to be 2.464 million litres of sewage, while decreasing water pollution levels and improving water quality in Mumbai’s Mithi and Oshiwara rivers.
Also building of the Mithi River Water Quality Improvement Tunnel is up to a refurbished Terratec 3.14m diameter EPBM. Previously used for the completion of the Mumbai Sewer Disposal Project (MSDP) Stage-II Priority Works, it is expected to make its second breakthrough next week. The intended EPBM that is operated by a J Kumar Infraprojects and MEPL joint venture,has achieved a monthly advance of 370m.
