Laboratory Investigation on the Effects of Natural Fracture on Fracture Evolution of Granite Exposed to Freeze-Thaw-Cyclic (FTC) Loads

Table 3

Percentage of the low, medium, and high frequency AE signals during rock deformation for the typical samples.

Sample ID	Initial damage degree (%)	Ratio of low frequency (%)	Ratio of median frequency (%)	Ratio of high frequency (%)
NFG-34	0.19%	64%	26%	10%
NFG-24	0.15%	70%	18%	12%
NFG-21	0.13%	51%	30%	19%
NFG-30	0.11%	45%	24%	31%