Modélisation géostructurale 3D de parois rocheuses par lasergrammétrie et photogrammétrie terrestres en milieu ferroviaire

Rock instabilities located along the national railway network are a real risk for safety and regularity of rail traffic. The project presented in this paper aims to optimize the methodology for geostructural characterization, resulting in an improved knowledge of the rock mass and better management of associated hazards affecting the railway system. As a consequence, a new approach is proposed in order to study the outcrops with the joint use of dense three-dimensional data and 2D digital images obtained by terrestrial laser scanning and photogrammetry. Using semi-automatic and/or assisted manual processing, the analysis of point clouds and photographs ultimately allows access to the main quantitative parameters characterizing the structure of the modeled rock walls. This set of developments has been integrated into a functional modeling tool: GAIA-GeoRoc. On the one hand, it makes massive amounts of dimensional data available to geologists; on the other hand, in a railway context, it improves our knowledge of the rock masses without risking the safety of personnel (thanks to non-contact measurements) or reducing the railway line capacity.