Protection of Transmission Line Towers during Landslides - A Case Study

North East Transmission Company (NETC) is entrusted with construction and maintenance of it's 662.8 Km, 400 kV Double Circuit transmission line in the difficult hilly & dense forest terrain in the states of Tripura, Meghalaya and Assam in the North Eastern Region (NER) of India. The terrain consists of various types of soils viz. laterite, alluvial, loamy, red soil etc. and is prone to sinking and landslides due to steep gradient and soil characteristics accompanied with heavy rains in NER. The transmission line route traverses through areas of high rainfall, wind zones of V & VI and high Isokeraunic level.

NETC is regularly facing the soil erosion/land slide issue in various tower locations of Pallatana -Silchar Line section. The deforestation due to development and various construction works coupled with incessant heavy rains of NER are some of the reasons behind such landslides.

This paper strives to describe various types of challenges being faced by NETC in operation and maintenance of the line with respect to landslides, sinking of hills, soil erosion etc. and the mitigation measures adopted by NETC like providing bamboo palisading, retaining wall, maintaining the natural vegetation and taking up plantation near tower foundations.