Deformation Field of Limestone Specimen under Uniaxial Compression Loads Using Video Images

摘要

The original images were obtained from the uniaxial compression tests of limestone and transformed into the static and responding grayscale ones. The displacement field was computed using the particle image velocimetry technique. The strains were obtained from the displacements using the local least square method and investigated at different locations. It was found that the deformation changes steadily followed by a rapid increase as time passes and only a few of them had been developed into the visible cracks, although several deformation concentrations occurred in the specimen under the compression loads. The techniques presented herein provide valuable information in investigating the failure mechanism of the rock materials.