The project is located in the Himachal Pradesh state of India and almost 40 km to the east of Kalpa. The power house below a cut and natural slope needed protection against rock falls. Similar to the power house the surge shaft cut also required to be supported by rockfall barrier and rock fall net.
Geology: The project area lies in Mehbar and Maldi gneisses comprised of kyanite and psamatic gneisses with bands of schist and quartzite. These are intruded by basic and acidic rocks. Some of the rocks are well folliated. The general trends are North-South with moderate trend towards East. These are transacted by number of joints of which the folliation and strike joints are most predominantly followed in frequency by steeply dipping transverse joints.
The authorities decided to apply rockfall protection barriers from Geobrugg. With its ring nets made of high-tensile steel wire, the barrier design was tested and approved to absorb impact energies of up to 8000 kJ.
GBE-2000A of length 50 meters and GBE-1000A of length 30 meters were installed.
The authorities also decided to install flexible slope stabilization system QUAROX® rolled cable net, with GEOBRUGG SUPERCOATING® and high-tensile rockfall protection netting DELTAX® G80/2 (Secondary mesh)
Area: 13500 sq.m. Variable grid pattern and fully grouted rock bolts of diameter 32 mm / length 3 m, fully threaded with top 6" galvanized material, Grade EN8, Ft = 500 N/mm².