Abstract: In order to accurately measure the sample deformation in the triaxial shear tests, this paper presents a deformation measurement by using photogrammetry method. The image data acquisition was performed by an IPhone 6 cell phone on the RDA codes on the triaxial shear soil samples. The sample deformation model was established through the camera calibration, image processing and three-dimensional deformation reconstruction so that the sample deformation could be obtained. The results indicate that this method is feasible and effective and the advantages of using IPhone 6 cell phone for the image acquisition are easy to use and save both time and cost.

Key words:  IPhone 6 cell phone, photogrammetry, camera calibration, threedimensional deformation reconstruction