431 meters of the Vishnugad-Pipalkoti Hydropower Project has been excavated
On the Vishnugad-Pipalkoti Hydropower Project in India, Terratec’s Hard Rock Double Shield Tunnel Boring Machine (TBM) is accomplishing noteworthy milestones. In January, the Ø9.86m TBM successfully excavated 431 meters, which was a significant project advancement.
The Vishnugad-Pipalkoti Hydropower Project is located 500 kilometers northeast of Delhi in the state of Uttarakhand and involves the construction of dams, waterway tunnels, vertical shafts, and a 444MW powerhouse. With the purpose of building a low-pressure head race tunnel that is essential to the hydroelectric power system, the Double Shield Tunnel Boring Machine was created. Custom features on this TBM are intended to complete the 13 kilometer tunnel.
The project’s alignment mostly follows Dolomitic limestone (33%) and slates (64%), with the final 3% going through areas of important geology. Thrust Zones, Shear Zones, and Fault Zones are some of the portions that provide serious obstacles and call for the specific engineering of the TBM. For the project, Terratec is also supplying the Continuously Advancing Tunnel Conveyor.
The 13km Continuously Advancing Conveyor is engineered to fulfill the unique requirements of the project and will run at a speed of 1200t/h. Throughout the whole tunnel, the conveyor can effectively handle the different materials that the TBM extracts. It’s expected that the materials being delivered will range from rocks to sand gravel.
By matching the steering/rolling position of the TBM, Terratec’s proprietary Advancing Tail Piece design uses an active hydraulic system to level the Tunnel Conveyor. This makes it possible to negotiate any curve, both vertical and horizontal, with ease.
With twelve huge bucket holes and 19″ disc cutters, the TBM‘s Cutterhead facilitates excavation into hard rock thanks to its 4,200kW electric main drive, which produces torque greater than 22,000kNm. Universal reinforced concrete lining rings, each measuring 1,500 mm in width and 350 mm in thickness and consisting of five segments and a key, are installed as the TBM advances.
The Vishnugad-Pipalkoti Hydropower Project involves the construction of a 65-meter-tall diversion dam over the Alaknanda River as part of a run-of-river system. A 237-meter gross head will enable power generation. 2.47 million cubic meters of the reservoir’s 3.63 million cubic meter gross storage capacity will be used for live storage. The water conductor system consists of two distinct subterranean caverns for turbine and transformer installations, as well as intake tunnels, headrace tunnels, subsurface sedimentation chambers, surge shafts, pressure shafts, and penstocks.
With the Vishnugad-Pipalkoti Hydropower Project built for 1657.09 MU energy generation, the addition of 444MW capacity in the Northern region will greatly ease peak power shortages. Notably, 1% of Uttarakhand’s 13% allotted free power would go toward local area development.