中文摘要：

粉土具有明显的非饱和土力学特性,坡内外水位变化诱发粉土边坡失稳是常见工程灾害之一。分别针对坡内和坡外水位变化诱发的粉土边坡失稳情况,开展了相应的离心模型试验研究,结合非饱和土力学相关理论分析和数值模拟,揭示了粉土边坡在两种情况下的变形及失稳模式和发生机制。结果表明：当坡内水位超过1/3坡高后,在坡内渗流作用下,粉土边坡呈现逐级侵蚀剥落、从坡脚向坡顶、由浅层向深层的多级滑坡失稳;坡外水位上升将导致松散粉土边坡发生显著湿陷变形,而坡外水位骤降将造成粉土边坡的多重浅层牵引式滑坡。粉土边坡的失稳模式和发展与粉土的非饱和土力学特性密切相关。最后根据模型试验结果提出了相应的粉土边坡渗流失稳工程控制措施。

英文摘要：

Silty soil has obvious characteristics of unsaturated soil mechanics.The failure of silty slopes induced by change of water level inside and outside them is one of the most common engineering disasters.Two centrifugal model tests associated with the corresponding theoretical analysis and numerical simulation of unsaturated soil mechanics are carried out.The two model tests reveal the deformation,sliding mode and failure mechanism of the silty slopes.The test and numerical results show that if the water level inside the silty slopes is higher than one-third of the slope height,multi-landslide will progressively occur from the toe to the top and from the shallow layer to the deep one.The rise of the outside water level causes obvious collapse deformation inside the slope,and the drawdown of outside water level results in shallow multi-landslide.The failure of the silty slopes is closely related to the behaviors of unsaturated soils.Finally,a series of engineering measures to control the failure of the silty slopes are proposed.