Deformability characteristic of rock mass is assessed on the basis of classical elasto-plastic theory. But, the analysis is
based only on the concepts of stress and strain, and may not be sufficient enough to assess the actual deformational behaviour,
as the evaluation procedure established by the standards considers only the deformation at the peak stress levels and not the
complete stress-deformation behaviour of rock mass. Also, the stress-deformation behaviour of rock mass, describing its specific
mechanical state, is only one aspect. The deformation of rock mass is partially irreversible process involving energy dissipation.
The application of external forces changes the stress and deformation distribution within the rock mass, while at the same time
some of the dissipated energy creates damages/ plastic deformation in the rock mass. This paper establishes a framework to
facilitate the study of energy conversion that occurs during the deformation of rock mass in in-situ plate load test.
