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为研究西北地区特殊的黄土–泥岩二元结构边坡地震动响应机制,以天水地区典型边坡和滑坡为原型,采用黄土–泥岩组合的概念模型,设计并完成比例1∶40的离心机振动台试验。在满足相似律的条件下,通过输入不同振幅的水平向和垂向地震波,系统地研究模型边坡的地震动力响应特性。以输入加速度峰值0.1 g为例,对这2种边坡模型的动力响应及破坏特征差异进行分析,结果表明:2种边坡关键点位的动力响应水平向大于垂向,呈非线性,并表现为趋表效应、高程效应和岩性效应;一般黄土边坡的破坏形式表现为:坡肩形成拉张裂隙,逐渐扩张,坡肩产生向临空面方向的位移,坡体中上部的黄土覆盖层隆起,部分土体振松滑落堆积在坡脚;黄土滑坡的破坏形式表现为:滑坡后壁形成拉张裂隙,逐渐扩张,滑坡后壁发生崩落,滑坡顶部堆积体略有下挫,形成凹槽,坡脚发生轻微鼓胀。
In order to study the earthquake response mechanism of the special loess-mudstone binary structural slope in Northwest China, taking the typical slope and landslide in Tianshui area as the prototype, a conceptual model of loess-mudstone combination was used to design and complete the centrifuge shaking table test. Under the condition of meeting the similarity law, the seismic response characteristics of the model slope are studied systematically by inputting horizontal and vertical seismic waves with different amplitudes. Taking the input acceleration of 0.1 g as an example, the dynamic response and failure characteristics of the two kinds of slope models are analyzed. The results show that the dynamic responses of the two kinds of slope are greater than the vertical and nonlinear, and Which is manifested as surface effect, elevation effect and lithology effect. The damage forms of loess slopes are as follows: the sloping shoulders form the tension cracks and gradually expand, the displacement of the sloping shoulders to the facing surface, the loess Some of the loess landslide sloshing and falling on the foot of the slope. The damage forms of the loess landslide are as follows: the rear wall of the landslide forms a tension crack and gradually expands, and the rear wall of the landslide breaks down. The accumulated body at the top of the landslide slightly descends to form a concave Groove, slope foot slightly bulging.