Abstract:Along the Karakorum Highway (KKH) that is the key route for the China-Pakistan Economic Corridor, it is wide existence of rockfalls and instable slopes that are usually caused by the tectonic movement and rainfall on the fractured rocks and slopes. This paper presents a numerical investigation of rockfall and slope stability along Karakorum Highway in Jijal-Pattan Northern Pakistan by using DIPS, GeoRock 2D and SLIDE, with attracting a focus for rockfall and slope stability along KKH to develop their countermeasures. Along KKH, two major susceptible sites were selected to investigate the rockfall and slope instability mechanism. The stereographic projection analysis following four sets of joints indicates that both sections are prone to plane failure and wedge failure. Based on the limit equilibrium theory, under static loading, the slope for section 1 showed a stability coefficient of 0.917, representing its instability, and the slope in section 2 has a stability coefficient of 1.131 depicting its slight stability. However, for both sections under the seismic condition, the stability coefficients of the slopes were lower than 1, which indicates their instability. The results by GeoRock 2D reveals that the fallen rock mass have attained the bounce height of 33 m and 29 m in section 1 and section 2, respectively. The fallen rocks in section 1 has the total kinetic energy of 1135.099 kJ with the velocity from 0.5 m/s to 44 m/s, while in section 2 the fallen rocks has the velocity in a range from 0.5 m/s to 40.901 m/s with a damage capacity of 973.012 kJ. This study showed a great damage potential of the rockfalls and landslides along KKH, which would be a reference for the design of the countermeasures of rockfalls and landslides.