摘要
以甘肃天水海头村黄土–风化岩接触面型斜坡为研究对象,基于振动台模型试验研究不同地震动强度条件下斜坡坡面变形破坏特征。分析裂隙产生、坡面剥落、坡体崩塌滑动3个阶段竖向裂隙的发展过程。结合土体应变测试结果,揭示该类斜坡失稳机制及滑移面衍生规律。研究结果表明:相同烈度地震动强度荷载作用下,垂直向加载对模型产生的影响小于水平向加载。地震荷载作用下,土体垂直向易产生纵向裂隙,水平向易产生横向裂隙。竖向裂隙是坡表土体破碎的主要原因,横向裂隙发展是导致斜坡失稳的主要内驱。顶部土体在地震荷载作用下发生张拉和剪切的复合破坏,导致坡表横向裂隙向下延伸至黄土–风化岩接触面并形成该类斜坡失稳破坏的滑移面。
Based on the shaking table model test,the characteristics of deformation and failure of the slope under different ground motion intensity are studied in the loess-weathered rock contact surface slopes in Haitou Village,Tianshui,Gansu Province. Furthermore,the development of vertical cracks during the period of crack generation,surface peeling and slop slide were analyzed. Combined with the results of soil strain test,the mechanism of the slope instability and the derivation of the slip surface are revealed. The results show that the influence of vertical loading on the model is less than that of horizontal under the same seismic intensity. The vertical direction of soil is easily to induce vertical crack while the horizontal is more intend to induce transverse crack. Moreover,vertical crack is the main cause of surface friability,but transverse crack is the main driving force of slope instability. At the top of the slope,the composite failure of tension and shear occurs under the action of seismic load,which leads to the downward transition of the transverse surface of the slope to the contact surface of the loess-weathered rock,forming the slip surface of the slope failure.
引文
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