Road Stabilisation through Geosynthetics in Slide Prone Areas of Tala Hydroelectric Project in Bhutan, Himalayas

This paper highlights the geosynthetic techniques applied for road stabilisation through the slide areas in eastern Himalayas for implementation of 1020 MW capacity Tala Hydroelectric Project in south-west Bhutan. About 115 km of hill roads had to be freshly cut to approach various components of the project. These formation cuts in the fragile Himalayan geologic formations underwent numerous occurrences of bench settlements, slides, slips, damages to retaining structures and failures of subgrades/road surfaces. Stabilisation solutions were evolved quickly by supplementing the age-old tested methods with the “geosynthetic techniques”. The paper focuses on tackling major problems encountered on the vital 26 km long road connection to the powerhouse area of the project and dwells in detail on the application of geosynthetics in the form of nets, meshes and mats for immediate as well as long-term protection measures.