Geoengineering in Landslides Mitigation Experiences from Nepal Himalayas

Abstract

 The engineering geological diversity strongly influences landslide occurrences and road-slope stability. The Terai faces settlement, subsidence, and erosion in alluvial deposits, while the Siwalik is characterized by weak sedimentary rocks, differential weathering, and rainfall-induced failures. The Mahabharat Range experiences instability associated with steep terrain and fractured rock masses. In the Midland region, foliated metamorphic rocks, weathering, and groundwater contribute to shallow and deep-seated landslides. The Higher Himalaya is susceptible to rockfall, rockslides, and debris flows due to steep topography and fractured crystalline rocks.

These contrasting conditions require engineering geology-specific mitigation measures, including drainage improvement, slope regrading, rock bolts, retaining structures, bioengineering, and rockfall protection. Integrating engineering geological mapping, geotechnical investigation, stability analysis, and monitoring is essential for selecting effective and sustainable road-slope stabilization measures.