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

Table 1

Testing scheme for the naturally fractured granite under uniaxial cyclic conditions.

Testing group	Sample ID	()	Ms1 (g)	Ms2 (g)	Mass loss rate (%)	Initial damage degree (%)	Loading and unloading conditions
I	IG-1		572.3	/	0.13%	0	Uniaxial, monotonous compression, 0.06 mm/min
	IG-2		568.6	/	0.11%	0
	IG-3		570.6	/	0.15%	0
II	NFG-34		565.6	562.6	0.53%	0.19%	Uniaxial cyclic, static loading, loading rate 0.06 mm/min, unloading rate 0.03 mm/min; increasing amplitude stress of 10 MPa
	NFG-24		559.8	557.3	0.42%	0.15%
	NFG-21		564.1	562.1	0.37%	0.13%
	NFG-30		552.3	550.6	0.31%	0.11%

Note: the initial damage degree of the samples was defined as the ratio of natural fracture volume to the sample volume.