铜质模型桩加固边坡的动力离心模型试验研究

Dynamic centrifuge test of slope reinforced with copper model piles

地震作用引起的边坡大变形常会使边坡稳定性丧失或使加固措施失效,动力离心模型试验是研究地震作用下边坡土体与抗滑桩的动力相互作用的有效手段之一。本文采用铜质抗滑模型桩制作了抗滑桩加固边坡模型,通过动力离心模型试验研究了地震作用下边坡变形、土体加速度反应和抗滑桩静力、动力弯矩等动态反应。试验表明:边坡的地震加速度反应自下而上逐渐放大,桩体附近土体的加速度反应略有减小;抗滑桩弯矩随着地震作用增强而相应地增至峰值,此后随着地震作用的衰减而下降,地震结束后承担着震后残余弯矩,该弯矩值仍大于震前静力弯矩;通过比较震前与地震中抗滑桩弯矩分布的变化可以看出,地震作用导致的最大附加弯矩为202 kN.m,相当于静力弯矩的36%,表明地震作用导致的附加弯矩不容忽视。

The effect of the seismic response on stabilizing piles and soil-pile interaction in the slope is potentially significant. In this paper, by making use of the copper model piles, the dynamic centrifuge test of soil slope reinforced with one row piles was performed. The soil arc effect around piles and displacement of slope were observed. Furthermore, this paper also discussed the distinctive characteristic of the seismic acceleration response and the moment histories of piles, and evaluated the excess dynamic moments resulted from the input earthquake motion. The observation and the test results exhibited the phenomena that the excitation of the earthquake makes pile＇s moments increase sharply and after the earthquake the residual moments of piles are more than the values of static moments. The acceleration responses are enlarged gradually from the bottom to the top in the slope.