Strength and Microscopic Damage Mechanism of Yellow Sandstone with Holes under Freezing and Thawing

Table 4

Fitting curve related parameters.

Test piece condition	Combined function
	a	b	c	R^2
	Hole diameter d = 6 mm	0.038	1.05	0.59	0.91
Hole diameter d = 8 mm	0.85	1.01	0.94	0.8
Hole diameter d = 10 mm	0.88	1.09	0.65	0.73
Hole diameter d = 12 mm	0.98	1.2	0.37	0.92
Freezing and thawing times n = 5	0.94	1.06	1.86	0.94
Freezing and thawing times n = 10	1.05	1.01	0.55	0.87
Freezing and thawing times n = 20	1.13	0.84	0.28	0.85
Freezing and thawing times n = 40	1.18	0.79	0.45	0.71