Study of scale effects on the deformability modulus of rock by means of a discontinuous model
The aim of this article is to investigate the effects of scale phenomena on the deformability modulus through an analysis of the mechanical behaviour of specimens of different sizes containing various geometric discontinuity configurations. In order to determine the modulus of deformability of a specimen, a uniaxial compressive test is simulated with the aid of a numerical computation code, which is based on fracture mechanics. In particular, the code was applied to a renormalisation process: as their size increases, the specimens display larger sized cracks but they are seen to be made of a material with a reduced deformability modulus on account of the presence of smaller sized cracks whose value is known from the analysis of smaller specimens. This approach makes it possible to show that the modulus decreases with increasing specimen size with a linear evolution on a semi-logarithmic scale.