Research Article

An Evaluation Method of Rock Brittleness Based on the Prepeak Crack Initiation and Postpeak Stress Drop Characteristics

Table 1

Calculation results of the brittleness index for marble under different confining pressures.

Confining pressure (MPa)Peak strainCrack initiation strainStrain differenceBiBiiBIQualitative analysis of the test curve
εc/%εci/%△ε=εcεciεci/△εS/SBi·Bii

50.0039800.0012500.002730.460.330.152Brittleness
150.0071700.0021700.005000.430.250.110Elasticity-plasticity
250.0075700.0024400.005130.480.170.082Elasticity-plasticity
350.0118200.0027300.009090.300.260.078Elasticity-plasticity