Description of a fracture morphology in regard of its behaviour during shearing

The understanding of the mechanical behaviour of rock joints during shear displacement needs an accurate description of the morphology of both walls of the fracture. This paper is a contribution to the very detailed description of the fracture asperities distribution. Asperities are any features of whatever size contributing to the roughness of the walls of the fracture. Assuming fracture surfaces are looking like a geomorphologic landscape, asperities are considered to be local or regional rough patches lying between catchment basins. Image analysis and specially mathematical morphology associated with geostatistical methods are very useful and efficient tools in order to characterise the roughness of a fracture.