Digital Image Processing Technique for Improvement in Triaxial Test and Numerical Modeling of Geomaterial

A contactless inspection method based on digital image processing technique is introduced to improve measurement of specimen deformation in triaxial test of geomaterials. Based on this method, a series of conventional triaxial compression tests under different stress paths are investigated. Then an elastoplastic constitutive model of soil is acquired through the numerical method of modeling constitutive law for geomaterial. Two examples of specimen deformation are presented and discussed. It indicated that the measurement precision on digital image process for column deformation is 0.01 cm³, prior to that of conventional method 0.1 cm³. Furthermore, the digital method for modeling can rationally simulate the stress-strain relationship of soil, which can reflect the effect of stress paths on soil stress-strain relationship.