An Approach to Limit Fully ConcreteLined Length of Pressure Tunnel for the Hydropower Projects to be built in the Himalaya

Abstract

The use of underground space such as waterway tunnels, shafts, underground caverns are inevitable in the development of hydropower projects in the Himalaya. Finding innovative solutions in underground construction is therefore key issue for financially viable hydropower development. Since, the traditionally used fully concrete lined waterway system has proven to be costly solutions, innovative solutions are needed to reduce the fully concrete lined length of the pressure tunnels. However, the solutions applied must guarantee long-term stability and sustainability, cost effectiveness, and construction time savings. This paper presents some design considerations that could be used to reduce fully concrete lined tunnel length for low to medium pressure waterway tunnels. Adoption of such an approach will drastically reduce overall construction costs and times. Brief highlight are also med on the existing design aspects, tunnel construction methods and challenges associated with Himalayan geology.