ABSTRACT
Chapter 5 discusses the shear strength of discontinuities and of rock masses in terms of Mohr–Coulomb properties of cohesion and friction angle. With respect to discontinuities, shear strength values are required for the rock surfaces, incorporating the roughness component and infillings properties, as appropriate. The direct shear test for measuring the friction angle of discontinuity surfaces is described. With respect to the shear strength of rock masses, values obtained by back analysis are listed, and the Hoek–Brown rock mass strength criterion is discussed in detail for both fractured and weathered rock. Also discussed are point load and slake durability tests.
