高心墙堆石坝地震残余变形和破坏模式的试验研究

Shaking Table Model Tests on Seismic Residual Deformation and Damage Pattern of Shuangjiangkou High Earth-rockfill Dam

为了解模型坝地震残余变形的分布规律和破坏形态,进行了不同地震波输入的振动台试验。坝体的沉陷和水平变位总体量值很小,地震残余变形主要发生于下游坡河谷坝段附近;坝顶有少量沉降变形和下游坝坡浅层滑动,而上游坡未观察到明显的水平变位或沉陷;下游坝坡的颗粒松动,发生滚石或浅层滑动,并首先发生于坝顶河谷坝段附近,且随着地震动的加大,范围逐渐扩大,但没有发现深层滑动的迹象;坝体自振频率降低越多,说明振动对坝体造成的损伤越严重;双向或多向地震动输入不利于坝坡的稳定。

In order to understand the distribution law of seismic residual deformation and the possible failure pattern of model dam were studied,make the shaking table model tests input by different earthquake wave. The research showed that：the settlement and horizontal displacement of dam body are small, and the seismic residual deformation mainly appears on the downstream slope in the middle section of the dam;it is crest settlement and downstream slope＇s superficial sliding, while there is no obvious settlement or horizontal displacement on the upstream slope;dam is the particle loose, rolling stone and superficial sliding, which first occurs in the downstream surface of dam,and it develop with increasing of earthquake intensity, and no deep sliding occurs finally;the more the self-vibration frequency decreases, the more serious the dam body is damaged by the vibrations; the earthquake was dynamically input in two-direction（x,z）or in three-direction（x,y,z） is unfavoratle to the stabiliy of dam slope.