Digital image correlation analysis (intact rock wetting test)

Abstract

In order to evaluate the effect of moisture on the deformation of an unsaturated granite, we used the digital image correlation (DIC) method to measure the surface deformation of a Herrnholz granite prism (63 × 90 × 33 mm, width: height: thickness) undergoing progressive wetting due to a film of distilled water maintained on its upper surface. The DIC analysis was undertaken using the open-source 2D digital image correlation software Ncorr. It tracks surface deformation by correlating the best fit between pixel values within a defined search window in images taken during progressive wetting of the sample to those in the reference image acquired immediately prior to the water introduction.