Terrestrial photogrammetry at the quarry and validating the accuracy of slope models for monitoring their stability

Abstract

The paper is devoted to the application of photogrammetry in surveying and geomechanical studies of the state of stability of slopes in a quarry. For deep quarries a particularly important task is to ensure the stability of the slopes of the benches. The purpose of this study is to improve the survey techniques of the slopes using terrestrial photogrammetry, the establishment of the values of the basic errors in the positioning of cameras in local geodetic network. The results of photogrammetric measuring data processing, which are the coordinates of the slope points and its elements, point cloud, surface model, volume and area data, improve the quality of geomechanical monitoring at mining enterprises and provide increase safety of mining operations. The proposed method of survey consists in positioning images (projection centres) in the system of the geodetic reference network by measuring with an electronic total station. Established during the study was dependence of the accuracy of the coordinates of the three-dimensional model of the slopes on the distance between the camera and the total station, between the camera positions in a pair of images. The article contains the results of the practical implementation of the proposed survey method, the results of experiments performed for the purpose of comparison with an alternative measurement method, which was a survey by a total station, graphs of dependencies describing the effect of measurement parameters on the accuracy of work performed. The article is also supplemented by a theoretical analysis of the use of UAVs in the use of work to determine of stability of slopes in a quarry, which is based on the authors' experience with the use of UAVs in open pit mines. In this theoretical comparison, the emphasis is mainly on the operability of the use of UAV, which in the case of open pit mines creating a practically stable wind vortex with a speed higher than the allowed speed of operation rotors UAVs.