Determination of Joint Shear Strenght using Photogrammetry

Abstract: This master thesis presents the development and finalization of a procedure document useable for determination of joint shear strength. The procedure is presented as a step by step instruction ranging from the imaging of a rock sample to evaluation of the acquired data and the generation of a numerical model.
Imaging is performed using a Camera with a fixed lens in combination with the photogrammetry software 3DM CalibCam and 3DM Analyst. The resulting photogrammetry data is exported in the form of a data terrain model (DTM). The DTM is used to generate the input to a numerical shear-box model using a combination of Microsoft Excel and numerical analysis (UDEC). The shear box model emulates a push-pull test where the upper block is forced to move across the surface of the lower block while subjected to a constant normal load.
Evaluation of the DTM accuracy is carried out by means of a laser scan. The DTM and the laser scanned surface are compared using computer assisted design (CAD) software. The comparison proves that the DTM is accurate on a scale smaller than one millimeter.
As part of future research, calibration of the model will be performed using shear strength data from actual push pull test on the same block sample. The constant normal stiffness will be taken into account by an alteration of the boundary conditions.