Institute of Mountain Hazards and Environment, Chinese Academy of Sciences (CAS)
The Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA20030301) and "Belt & Road" international cooperation team for the "Light of West" program of CAS (Su Lijun)
作为中巴经济走廊的重要通道，喀喇昆仑公路沿线广泛存在因构造运动和降雨触发的落石和不稳定边坡。本文通过使用数值软件（DIPS, GeoRock 2D and SLIDE）对巴基斯坦北部吉贾尔-帕坦喀喇昆仑公路沿线的落石和边坡稳定性进行了数值研究。本文以喀喇昆仑公路沿线的两处典型边坡为例来研究落石和边坡非稳定性机理。四级节理的赤平极射投影分析表明：两处断面均易产生平面和楔形边坡破坏。基于极限平衡理论，静力条件下，0.917安全系数表明断面1边坡处于不稳定状态，而断面2边坡的安全系数为1.131，处于欠稳定状态。然而，地震条件下，两处断面的边坡安全系数均小于1，均处于不稳定状态。GeoRock 2D研究结果表明断面1和断面2边坡的落石回弹高度分别为33米和29米。断面1边坡的落石速度在0.5米/秒至44米/秒，总动能达到1135.099 kJ。而断面2边坡的落石具有每秒0.5米至40.901米的速度和973.012 kJ的破坏能力。本研究表明了喀喇昆仑公路沿线落石和滑坡具有极大的破坏能力，其研究结果将为落石和滑坡对策设计提供参考。
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.