Behaviour of sands
Granular materials like sands and gravels are free draining soils. Their stress-strain strength properties are, then, determined in drained tests to simulate field behaviour. This chapter analyses the results of drained triaxial tests in sands, followed by an analysis of direct shear tests. It discusses stress-strain-strength properties, and factors that affect these properties. The effect of the initial void ratio and confining pressure is also discussed. The chapter also talks about the Mohr-Coulomb’s strength envelope and Mohr-Coulomb’s failure envelope. The following conclusions about the critical friction angle can be drawn. First, can be interpreted as a material property that is independent from the state. Second, is a conservative value for the friction angle, occurring at large strain. If it is used in the assessment of stability, the design will be on the safe side.