Fig. 8From: An approach to hydraulic fracture in geomaterials through a porous brittle damage material modelSensitivity analysis on friction angle. Failure surfaces in the Mohr plane for friction angles of 30, 38, 45\(^\circ \). Figure shows two Mohr’s circles corresponding to the geostatic state and to the state characterized by a fluid pressure able to cause the failure of the materialBack to article page