Innovative technique for replacement of ruptured steel liner of pressure Shaft of Parbati-II H.E. Project, NHPC Ltd, (H.P.)

Construction of Inclined Pressure shafts is usually most challenging job worldwide. While when it comes to replacement of any ruptured steel liner segment confronting heavy ingress of water from saturated hill mass coupled-with constrained working space, the difficulty level increases manifolds. This paper is a saga of rectification works-of steel liner taken up in each of the two nos 3.5 m dia, 1.5 km long inclined pressure shafts, at 30o inclination, of Parbati-II HE Project (800 MW) of NHPC Ltd. located in Himachal Pradesh, India. The replacement of 3 m long steel liner in each pressure shaft was accomplished successfully through in house engineering prowess of NHPC Engineers. The relentless efforts put forth by the NHPC Engineers paved way for successful completion of rectification works and project was made operational at part load by utilizing available water from Jiwa Nallah.