水位变动条件下土坡变形累积致损特性

水位变动易引起边坡破坏,造成巨大损失。合理评价水位变动条件下边坡安全性需要阐明其破坏机理,为此进行了水位变动条件下土坡离心模型试验。试验结果表明,水位变动首先在坡体中下部引起局部破坏,该局部滑裂面向上发展至坡顶形成了完整滑裂面。土坡破坏不是瞬时发生的,水位变动过程引起的变形局部化累积是土坡发生破坏的本质原因。水位变动导致土坡变形局部化程度单调增加,此外局部破坏在其附近引起新的变形局部化并在坡体内扩展。水位变动条件下土坡表现出变形局部化累积与破坏过程的显著耦合特性,这是土坡破坏分析方法需要合理反映的。

Slope Failure Due to Local Deformation Accumulation under Water Level Fluctuation

Water level fluctuation has induced a large number of slope failures, resulting in huge losses of life and property. Clarifying the failure mechanism is a requisite for a reasonable evaluation on slope safety under water level fluctuation condition. Such mechanism was investigated using centrifuge model tests in the present research. Test results demonstrate that water level fluctuation gave rise to local failure in the mid-lower part of the slope which developed upwards until the final slip surface was formed. The accumulation of local deformation, instead of instantaneous destruction, is the fundamental cause of slope failure under water level fluctuation. The local deformation developed monotonically and further triggered new local deformations around and extended in the slope. In summary, the extinct coupling of local deformation accumulation and failure process under water level fluctuation should be well considered in the analysis of slope failure.