Geomechanical parameters of intact rocks and rock masses from the Canary Islands: Implications on their flank stability

Abstract

New data on the geomechanical properties of the highly cohesive volcanic rocks of the Canary Archipelago and their role in the flank stability on oceanic islands are provided in this work. On the basis of the textural and petrological features, a preliminary classification of rocks, grouped into lithotypes, was carried out. This classification includes vesicular and non vesicular basalts, trachybasalts, trachytes, phonolites, welded and non welded ignimbrites. Strength and strain-related features are summarized here for each distinctive lithotype. Taking into account the results of the uniaxial and triaxial compressive tests, the geological strength index of rock masses and their textural–structural features, an estimate of the rock mass parameters and Mohr–Coulomb fit has been carried out. A final discussion on the impact of those geomechanical parameters as factors governing the stability of steep slopes in volcanic islands is then made here as a contribution in volcanic risk.