The morphology evolution of the shear band in slope: insights from physical modelling using transparent soil

摘要

Shear band propagation is the internal cause of the deformation and failure of landslides and is associated with much of the damage and loss of life. Understanding how the shear band develops will affect the process of slope deformation is thus of great interest. However, little investigation has been conducted studying the correlation between the slope deformation and the shear band propagation due to the inability to see through the shear band in traditional soil materials. By using transparent soil as a surrogate of natural cement soil, we achieve the visualization of the shear band in a laboratory slope model test, in which the failure was deliberately triggered by top-loading. The temporal evolution of the shear band length and the slope deformation are measured by tracking the tip of shear band and the feature points on slope surface using a commercial software After Effects. The spatial distribution of the shear band thickness and spatial deformation of the slope surface are separately measured based on the image measurement technology in OpenCV and PIVlab, respectively. The results suggest that the geometry of the shear band has a significant influence on the slope deformation. In particular, the velocity of the slope deformation changes synchronously with the speed of the shear band evolution. The spatial differentiation of the slope deformation exhibits a high correlation with the shear band thickness. This is the first time observing that the slope deformation at different locations can be combined to assess the slope stability more precisely by revealing the evolution of shear band geometry.