ROCK MASS DISCONTINUITY ACQUISITION BASED ON PHOTOGRAMMETRY OF UAV

At present, the methods for obtaining information of rock mass discontinuity mainly include artificial field contact measurement, three-dimensional laser scanning and close-range photogrammetry. With the maturity of UAV photogrammetry technology, the use of a UAV to survey all-around, multi-angle photography for the rock slope and establish a three-dimensional model for the slope can more comprehensively, accurately and efficiently obtain the information of the discontinuities. In this paper, the slope in Changchun Jingyuedongsheng quarry is used as the object of study. The phantom 3 of Dajiang UAV is used to photograph the slope, and the prism less total station instrument is used for slope control measurement. The Pix4Dmapper is used to establish the three-dimensional model of the slope. After the model checking with control points not involved in modeling, and meeting the accuracy requirements, the coordinates of the feature points of the rock slope discontinuities are measured on the model. Furthermore, combined with the discontinuity trace line display model and the model for calculating the orientation based on the three-dimensional coordinates. The trace lines and orientations of discontinuities are obtained. Compared with orientations that are measured artificially with compass, the precision of the orientation acquisition of the discontinuities based on photogrammetry of the UAV is obtained. The research shows that the information acquisition of rock mass discontinuity by photogrammetry of UAV is low in cost, low in labor intensity, high in efficiency, reliable in accuracy, and has broad application prospect.