【摘要】 为了研究双面高陡边坡破坏机理,以国道G213左侧双面高陡边坡为原型,采用新型离散元计算方法CDEM和振动台试验,模拟了高烈度地震作用下,双面高陡边坡上的坡积体滑坡由变形累计到破坏滑动的全过程.研究结果表明:在地震力和重力作用下,滑体顶部先出现应力集中,造成滑体沿滑体结构面后缘产生变形,进而造成该处出现拉伸、剪切破坏点;随着地震动的持续,滑体结构面上的剪切破坏点逐渐向滑体中前部的锁固段扩展,同时伴随着滑体表面拉伸破坏点的增加,最终造成锁固段发生渐进性破坏,滑体从剪出口滑出形成滑坡;在材料参数等外部条件相同的情况下,坡腰处滑体先于坡脚处滑体发生滑塌,滑塌发生的时间与地震动峰值加速度到达的时间同步或稍微有所滞后;以输入地震波为基准,不论是陡坡地形、缓坡地形还是坡体内,不同位置的峰值加速度沿坡高均有所放大,表现为竖向峰值加速度的放大效应大于水平峰值加速度的放大效应,陡坡地形峰值加速度的放大效应大于缓坡地形峰值加速度的放大效应,也大于坡体内峰值加速度的放大效应.更多还原

【Abstract】 In order to study the landslide mechanisms and responses of a high steep hill with two-side slopes under ground shaking,a high steep hill with two-side slopes near national highway 213 was used as a prototype.A full process from initial deformation to sliding of the slope during ground shaking was simulated by the continuum-medium distinct element method(CDEM).The results show that the stress concentration phenomenon appeared at the top of the sliding mass firstly,and then some tension and shear failure points appeared there,which expanded toward the toe of the sliding mass from the top along the structural plane.At the same time,the number of tension failure points gradually increased.Finally,the toe of the sliding mass broke,and the sliding mass sheared out from the toe,resulting in the landslide.If external conditions such as material parameters were kept the same,the landslide occurrence in the middle of the slope would precede that at the foot,and the starting time of landslide and the arrival time of peak ground acceleration(PGA) were synchronous or the former lagged behind the latter slightly.The PGA of the input seismic wave was amplified with the increase of elevation,regardless of on the steep slope,on the lower slope side,or inside the slope.Generally,the vertical PGA amplification is larger than the horizontal one;the PGA amplification on a steep slope is larger than on a gentle slope,and the PGA amplification on a gentle slope is larger than inside the slope.更多还原