Experimental application and accuracy assessment of 2D-DIC in meso-direct-shear test of sandy soil

Abstract

The examination of the meso-mechanical properties of soils is fundamental to understand its macro-behaviour. This paper aims to evaluate the potential application of Digital Image Correlation (DIC), an optical image processing approach, in direct shear test (DST) for soils. Hence, a new shear box was designed to investigate the close behaviour of granular materials. The noise-floor and shear displacement accuracy were discussed to assess the reliability of DIC, besides the effectiveness of the new box was also examined. The distribution of the displacements, strains, and shear angle were measured under four different normal stresses. From the results, the immediate settlement, and the dilative behaviour of the sand during shearing were observed. Furthermore, the investigation revealed a strain concentration at the interface between the boxes, where a shear band was formed. The use of DIC opens up new ways in soil mechanics, overcoming some limitations of the conventional DST