TERRATEC announced that the 9.86m hard rock double shield tunnel boring machine (TBM) has commenced the excavation for Vishnugad-Pipalkoti Hydropower Project in India.
The 9.86m TBM is currently working for Hindustan Construction Co. Ltd. of India which is the main contractor responsible for this project. The ongoing project takes place in the state of Uttarakhand, around 500 km Northeast of Delhi. The work involves the construction of dams, waterway tunnels vertical shafts and a powerhouse with a generating capacity of 444 MW.
The double shield TBM has been designed for the construction of a low-pressure head race tunnel, which is a crucial component of a hydroelectric power system. This TBM is equipped with customized features to efficiently complete the 13 km tunnel. The team has been waiting to complete the drill and blast section of the project.
The alignment for the Vishnugad-Pipalkoti Hydropower project comprises primarily of Dolomitic Limestone (33 percent) and Slates (64 percent), with the remaining 3 percent passing through critical geological sections. These sections include Thrust Zones (with shallow overburden of 150 m), Shear Zones (consisting of five zones), and Fault Zones (totaling three zones). These areas present significant challenges, and as a result, the TBM has been specifically engineered to handle these conditions. Additionally, TERRATEC is providing the Continuously Advancing Tunnel Conveyor for the project.
The cutterhead of the TBM features 19 in. disc cutters while maintaining 12 large bucket openings. The 4,200 kW electric main drive is designed to help the TBM to excavate through the expected hard rock, delivering a torque of over 22,000 kNm. As the TBM progresses, universal reinforced concrete lining rings, measuring 1,500 mm wide and 350 mm thick, are installed. These lining rings consist of five segments plus a key.
The TBM is equipped with features such as a high-speed regripping system, single-shield advancing mode, high-pressure emergency thrust, flood control doors, and numerous others. The key components of the TBM were manufactured in Australia and Japan, while the assembly took place at the TERRATEC facilities in China.
The addition of 444 MW capacity in the Northern region will significantly reduce peaking power shortages in that area. The project has a design energy of 1657.09 MU. Out of the 13 percent of free power allocated to the home state of Uttarakhand, 1 percent will be utilized for local area development.
TERRATEC has been chosen for the tunnel package in Vishnugad-Pipalkoti Hydropower Project due to TERRATEC’s continuing success on projects such as Phase III & IV of the Delhi Metro, Lucknow Metro, Pune Metro, Kanpur Metro, Ahmadabad Metro and Mumbai Metro. This is a result of tailor-made robust TBM design, prompt onsite assistance, readily available stock of TBM spares, and highly-skilled specialized TBM support throughout tunneling operations.