Failure in Continuum Geomechanics

In this chapter, the concept of failure is formalized starting from an energy approach where a deforming body under external loads is the point of departure. We are prompted with the intriguing question of what is the meaning of the second-order work. It will be shown that the second-order work naturally emerges from an energy balance written from the kinetic energy viewpoint - the well-known kinetic energy theorem. The second-order work is an important concept in solid mechanics that has been the object of numerous publications for the last several decades. However, it has not been fully applied in geomechanics where the notion of failure has not been thoroughly investigated from a mechanical viewpoint.