This study assessed the practice of slope stabilization along highway road between Mugling and Narayanghat with reference to existing scenario-highly unstable slope in Nepal. Slope instability issues mainly along Siwalik to lesser Himalaya region have become key and common problems. Geomorphological setting in that region is quite different from south to north profile of Nepal. The geological setting and structures are major factors which controls geomorphic features in Nepal. Several kilometers of highway corridor have been running along the mountainous region. The slope instability problems along road are mainly due to cut-off of mountain and their characteristics. Such issues along highway corridor highly influence overall road connectivity the country. Of many such issues, Mugling-Narayanghat Highway Road is considered to be lifeline in Nepal, which connects all parts of country with capital city Kathmandu. More than 20,000 vehicles have been running daily through this highway to all parts of Nepal from Kathmandu and vice-versa. The slope stabilization and management practice includes application of civil engineering and bioengineering techniques according to mechanisms of slope instability.
Major slope instabilities are related to mass-movements that have always been major problems in Nepal. The fragile geological condition and intense rainfall and topography of area leads gully erosion, riverbank cutting, landslides, debris flow, rock fall & rock slide and human intervention in the natural environment have been the major factors triggering the mass movement activities, which lead to several slope instabilities in Nepal. Landslides and debris flow have caused great damage to lives, property and infrastructure such as roads, and bridges.
The Mugling -Narayanghat section of highway road lies between latitudes of 27°45'00" to 27°52'30" and longitudes of 84°25'00" to 84°35'30" at the Central part of Nepal. This highway is well known as lifeline of Nepal. The 36 Km. long stretch of Mugling -Narayanghat highway connects East-West Highway (Mahendra Highway, India Border), Prithvi Highway (Kathmandu-Pokhara-Baglung-Jomsom-Korolla, China Border) and Araniko Highway (Kathmandu-Kodari, China Border), Kathmandu-Trishuli-Dhunche-Syaprubesi-Rasuwagadhi, China Border). It is a major part of Asian Highway and also connects capital city Kathmandu with other parts of country as well as helping develop international connectivity. This highway was constructed in assistance of Peoples Republic of China. Previously this was single lane highway. Recently, it has been extended in double lane since vehicle density and inter-road connectivity have been rigorously increased in the country for decade.
