已有研究结果表明,强度相对较低的软弱夹层会对地震波产生吸收或强化作用,在一定程度上控制了斜坡的地震动力响应及变形破坏特征。试验以振动台为研究手段,设计并完成含不同厚度水平软弱夹层的两个单面斜坡概念模型。通过记录斜坡模型的变形破坏过程,分析其动力响应特征。试验结果表明,斜坡模型的变形破坏与地震动力参数密切相关:1.模型在正弦波激振下较天然波变形明显;2.合成向ZX、水平单向X和竖直单向Z的激振下,变形程度依次减弱;3.随着激振强度增加,变形破坏愈明显。两模型的变形破坏均出现在坡体中上部,且最大破坏深度距坡顶约50 cm。含薄夹层斜坡的破坏范围分布于整个中上部,坡顶近1/2发生变形和滑移破坏,呈现出"拉裂-剪切-滑移-碎屑流化"破坏模式,而含厚夹层斜坡的破坏范围仅集中于软弱夹层以上坡肩以下,两侧未达坡体边缘的局部范围,形成浅表的"凹岩腔",呈现出"震裂-剥落"破坏模式。在相同的加载条件下,含薄夹层斜坡变形破坏先于含厚夹层斜坡。试验模拟再现了含水平软弱夹层斜坡在强震作用下的变形破坏规律,为地震诱发次生地质灾害的研究和防治提供了有力的依据。
Previous studies indicate that relatively low strength of weak interlayer can absorb or amplify seismic wave,and it controls to some extent the dynamic response and failure characteristics of slope.By means of shaking table test,two single-face conceptual models with different thickness of horizontal weak interlayer were designed.By recording deformation and failure process of the model,its dynamic response characteristics were studied.Test results show that the deformation and failure of slope are closely related to the seismic dynamic parameter.(1) Deformation of model is more obvious under the sinusoidal vibration than the natural wave.(2) The destruction of synthesis of excitations in ZX- direction,X- direction and Z- direction at the slope becomes weakening in turn.(3) With the increase of vibration strength,the deformation and failure becomes more obvious.The deformation and failure mainly appear in the upper part of slope model and the maximum damage depth reaches about 50 cm away from the top.For the slope with thin interlayer,the failure area distributes the whole upper-middle part of slope and nearly 1 /2 top of slope occur deformation and slip failure,which presents the cracking-shearing-slidingdebris flow failure mode.But for the slope with thick interlayer,the deformation and failure are confined the area above the weak layers and under the slope shoulder and both sides fail to reach the edge of slope body,which forms the superficial hollow and presents the shattering-scaling failure mode.Under the same condition of seismic wave,the deformation and failure of slope with thin interlayer priors to thick interlayer.The test simulated and reproduced deformation and failure law of slope with horizontal weak interlayer under strong earthquakes.It provided strong basis for research and prevention of secondary disaster because of earthquakes.