Thickness of the shear band of silty clay–concrete interface based on the particle image velocimetry technique

Abstract

The interaction between the interface of soil and concrete is the mechanical basis of engineering structures under loading. Many failures begin at the soil–concrete interface area in existing projects, so studying the interaction of the interface of soil and concrete is of great significance. In this study, digital images of soil deformation during the shearing process of silty clay–concrete interface were acquired in real time by using an improved visual direct shear apparatus and a high-definition industrial camera. The variation laws of shear band thickness under different moisture contents and normal stresses were analyzed by particle image velocimetry. The research showed that the introduced single change point of slope analysis method was able to determine the shear band thickness accurately, which was positively correlated with the normal stress and moisture content. Starting from the failure of the contact interface, the deformation within 5 mm of the interface was large. A shear band always appeared before the shear failure of the contact area.