为探究边坡受荷破坏时的剪切带形成机制, 设计室内模型试验. 模型试验采用数字图像相关 (digital image correlation, DIC) 技术, 表征和分析砂质边坡中剪切带的形成及边坡渐进破坏过程. 采用离散元软件 PFC3D 模拟模型试验, 对 DIC 计算结果进一步补充和验证.结果表明: 剪切带的发展是一个动态过程. 在加载初期, 剪应变区域分散在荷载周围. 随着加载的推进, 一些剪应变区域开始连接并形成多条剪切带, 而一些剪应变区域逐渐消失. 在 3/4T时刻左右 (T 为边坡达到极限承载力并发生破坏的时间), 多条剪切带转变为一条主剪切带, 主剪切带在 T 时刻前后延伸至坡面. T 时刻后, 滑移体的水平位移迅速增加, 表现为整体下滑.

In order to investigate the formation mechanism of shear band when slope was damaged by load, an indoor model test was designed. By using the digital image correlation (DIC) method, the formation of shear bands and the progressive failure of a sandy slope were characterized and analyzed in the model test, in which failure was deliberately triggered by loading. In this paper, the discrete element software PFC3D was used to simulate a model test to further supplement and verify the DIC calculation results. The results suggest that developing a shear band is a dynamic process. At the beginning of the loading, strain localization regions were scattered around the loads. As loading continued, some of the strain localization regions connected and formed multiple shear bands, while some strain localization regions disappeared. Around the time 3/4T (i.e., T was the time when the slope reached ultimate capacity and failed), multiple shear bands transitioned into one major shear band that extended to the slope surface around time T. After time T, the horizontal displacement of the sliding body increased rapidly, and the damage phenomenon manifested as an overall downslide.