中巴喀喇昆仑公路顺层岩质边坡受力分析

为了深入研究中巴喀喇昆仑公路洪扎河以北地段的顺层岩质边坡弯曲失稳机制,采用材料力学压杆稳定及刚性体平衡原理,在D.S.Cavers的基础上考虑地震力作用,分析得到岩质边坡的三种弯曲模型(平面边坡的柔性弯曲、平面边坡的三铰梁模型、曲线边坡的三绞铰模型)的失稳公式,将地震与非地震作用下平面边坡的柔性弯曲进行对比分析。研究结果表明:当内摩擦角φ_j处于0°~15°范围时,若水平地震加速度方向与岩体弯曲方向相反,平面边坡柔性弯曲模型在地震作用下不易发生弯曲变形;若水平地震加速度方向与岩体弯曲方向一致,地震作用下平面边坡柔性弯曲模型的临界状态总长度l总比非地震作用下的l小,平面边坡在此方向的地震作用下更易发生柔性弯曲变形。

Analysis on Rock Bedded Slope of Karakoram Highway,Pakistan

In order to analyze the mechanism of buckling failure of rock bedded slope in the north region of Hunza river along Karakoram highway, Pakistan, based on D.S.Cavers buckling formulas, the theory of column stability and principle of mechanical equilibrium is used to attain the failure formulas for three modes of buckling(flexural buckling of plane slopes, three hinge buckling of plane slopes, three hinge buckling of curved slope) under seismic loading. Then the failure formulas under seismic loading are compared with D.S.Cavers buckling formulas. The results show that, when friction angle is between 0° and 15°, if the horizontal seismic acceleration has the opposite direction with buckling, it is hard for flexural buckling mode of plane slope to buckle under the seismic loading; if the horizontal seismic acceleration has the same direction with buckling, the total slope length l in the critical condition under seismic loading is smaller than l without seismic loading. That is to say it is easier for plane slope to buckle under seismic loading.