Realtime Ground Monitoring of Geohazards Along Karakoram Highway at Michar District Nagar

Abstract

The study shows the investigation of slope failure at village Miachar, district Nagar.It also highlights the direct effect of the failure on Karakoram Highway. According to some studies this failure will cause irreversible catastrophe in the region. Approximates are that it will have 10 times the impact of Attabad incident This holds importance due to the fact that Karakoram Highway is the road link between Pakistan and China thus is an integral part of China Pakistan Economic Corridor (CPEC). Hunza River is flowing at the toe of this slope. Initially, in 1987, blasting sounds with movement in the ground was observed in this area. Its slope is approximately 50° from base. Furthermore, in 2010 till 2019, more movements were observed by locals. In 2019, with collaboration of NUST-IMH&E teams, different sensors were installed at different locations in this village. These sensors include five tilt meters, three extensometers and one rain gauge. The land of 800 meters height and around 1.5 to 2 kilometers in width has started settling since 2010. As a result it will also cause direct damage of KKH. So for this purpose soil samples were taken from the site to scrutinize its basic properties. These properties include moisture content, specific gravity, direct shear, sieve analysis, liquid limit, plastic limit and the soil classification tests. According to test results, target site is composed of silty sand with specific gravity (Gs) of 2.65 and Liquid limit of 25. It has angle of friction ()28° and cohesion factor (C) is 70 Kpa. Investigations unearthed that water has significant effect on the properties of soil. Visual survey of the site brought into light the fact that there is no proper drainage for water in the said region hence can be among the causes for failure. Undesigned and unplanned road construction may also be a reason Geological maps shows the composition of strata is Colluvium, Mica-Schist and Glacial Moraines which cause slope failure too. If this can be controlled in time, this catastrophe can be avoided.