A 3D image-based method to measure soil stiffness in triaxial tests

• DOI: 10.1007/s11440-023-01977-3
• Publication Date: 2023-07-06T10:01:52Z
• Authors: Zewen Wang; Wenhan Du; B. M. Lehane
• Keywords: Triaxial shear test; Soil test

Abstract This paper describes a new simple and inexpensive method for accurately measuring the three-dimensional deformation of soil specimens during triaxial tests. The incorporates cost-effective image capture system that can be applied to any apparatus as well an automated post-image analysis approach processing images acquired Image is performed using multiple low-cost Raspberry Pi cameras accessories placed outside chamber. employs particle velocimetry, camera calibration stereophotogrammetry determine spatial variation in axial radial sample strains samples are loaded. It demonstrated displacements measured with accuracy 1–2 μm, respectively, it verified by comparison data from tests on sand full nonlinear stiffness–strain degradation fully elastic conditions determined without need additional sensors.