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Titre : | Mise en place d'une chaîne de traitement pour l'étude et la gestion des chutes de blocs en montagne à partir de nuages de points obtenus par photogrammétrie : Application à deux falaises calcaires du synclinal chartreux oriental |
Auteurs : | Grégoire GIRAUD ; Héloïse CHAMPENOIS |
Type de document : | Mémoire d'initiation à la recherche |
Année de publication : | 2020 |
Concepts : | PHOTOGRAMMETRIE |
Résumé : | Rockfalls present a real and significant risk for both infrastructure and people. The work presented deals with the recent aim to use photogrammetry and 3D modeling of outcrops in order to replace the tedious and costly structural surveys. The first part of this work draws up the state of the art, both in terms of knowledge of the factors of slope stability and on the use of new telemetric techniques for the structural analysis of rock walls. To be illustrated, the work is based on a 3D outcrop model. The acquisition campaign and the regional context of the study area, the Chartreuse massif, near Grenoble in France, are developed. The presented methodology is based on the bibliographic analysis showing that studies assisted by 3D modeling commonly require the use of several software and that the processing of information most often required to be carrying out in different file formats, point cloud, mesh or orthophotographs before the possible extraction of morphological parameters. The proposed work focused on the presentation of tools allowing a homogenized use mainly supported on the point cloud for the search of these parameters. It relied on the use of CloudCompare, a point cloud comparison software enriched by many applications in recent years. The preprocessing of the data as well as the first results with the extraction of quantitative information on the morphologies present on the test model have been explained. On the basis of these results, the last part of this work is dedicated to the establishment of a treatment workflow. Its successive stages are criticized, and their limits are exposed in order to guide future work on this topic. The outcomes of this scheme allow to highlight the possibilities regarding the development of complete solutions in the study and management of the rockfall hazard. The first processing steps presented also make it possible to assess the potential of a partial automation. |
Spécialité : | Géologie |
Numéro de promo : | 82 |
numéro MIR : | 882 |