By rosebell
On Mumbai’s water network expansion, a breakthrough has been achieved on a 9.7km tunnel that is taking the system to more than 100km in length.
Through a Terratec open TBM with 3.2m diameter Soma Enterprise excavated the tunnel from Ghatkopar to Parel via Wadala.
Including a modular design, this machine enables both shaft launching and retrieval, ensuring flexibility during construction, whereas the cutterhead, equipped with heavy-duty back-loading disc cutters, is driven by VFD-controlled electric motors capable of achieving optimal torque and exceeding 10rpm rotation speed.
Considering that facing the diverse geological strata is important, the TBM is engineered with a comprehensive ground support system, including a fixed probe drilling unit, two rock bolting drills, a shotcrete pump, and a steel arch erector.
Additionally, TBM is designed for all components to be removed through the completed tunnel. The cutterhead has a flange, enabling it to be dismantled into two pieces for easy extraction.
As one of several projects being carried out by the Municipal Corporation of Greater Mumbai (MCGM), the Amar Mahal I water transfer tunnel comprises two TBM drives totalling 9.68km and is due to expand and improve its water distribution. The tunnel network lies at depths of 100-110m.
The date of completing Amar Mahal II Tunnel Project (AMT-II) in Maharashtra by Terratec’s 3.2m diameter hard rock open gripper TBM was February last year, that indicates Patel Engineering Ltd’s completion of two drives for the 5.53km-long water transfer tunnel contract.
