Researches on Damage Evolution and Acoustic Emission Characteristics of Rocks

Table 2

Confidence levels for the strength and elastic modulus of sandstone.

Confidence	Elastic modulus (GPa)	Strength (MPa)
0.90	15.32 + ∞	61.50 + ∞
0.95	14.82 + ∞	57.38 + ∞
0.99	13.59 + ∞	51.20 + ∞
Normal distribution	0.138	0.192
Logarithmic-normal distribution	0.146	0.205
Weibull distribution	0.053	0.116