Penstock slope stabilization using geogrids as reinforcements: A case study of Middle Tamor Hydropower Project (MTHP) – 73 MW

Slope stabilization is a major challenge in hilly terrains, especially for hydropower projects like the Middle Tamor Hydropower Project (MTHP). At MTHP, the penstock alignment’s stability was affected by excavation for saddle slabs and anchor blocks on a 90 m high slope composed of coarse silty sand with gravel, deposited by a natural outlet (kholsi). Continuous monsoon rainfall, tunnel muck dumping at the crest, and a rising groundwater table triggered slope creep and deformation. Due to tight deadlines, a reinforced backfilling solution using highstrength Paralink geogrid was adopted. This method enabled simultaneous slope restoration and saddle slab construction, improving structural stability while reducing construction time significantly