Weathering of the massiac gneiss (massif central,France)

Weathering profiles of gneissic rocks in tropical and temperate climates are here compared and represent a most relevant concern for geotechnical engineering. The understanding of the physico-chemical weathering processes is very important for an adequate interpretation of the geotechnical behaviour of those materials. The weathering profile of the Massiac gneiss developed in a temperate climate, is described in relation to its mineralogical and textural changes, as well as the characterization of the main index tests and geotechnical parameters as strength and deformability. The relevance of anisotropy in the different weathering grades is evaluated.