Method for measuring and calculating micro-scale strength and residual strength of brittle rock

The invention discloses a method for measuring and calculating micro-scale strength and residual strength of a brittle rock. The method comprises the following steps: carrying out a rock micron indentation experiment to obtain a rock loading and unloading curve and a micro-scale elastic modulus; deducing the relationship between the loading and unloading curve and the rock elasticity modulus, thepress-in depth, the initial strength and the residual strength based on dimensionless analysis of the Buckingham pi theorem; reconstructing a measuring point microscopic skeleton and a pressure head grid model through microscopic CT scanning; carrying out numerical simulation by combining parameters obtained through experiments with the Mohr-Coulomb criterion, obtaining the loading and unloading curves under different strength and residual strength, and fitting the relation between pressure head acting and the initial and residual strength of the rock under different characteristic press-in depths by means of a cubic