Application of Modified Hoek–Brown Strength Criterion in Water-Rich Soft Rock Tunnel

Table 2

Fitting formula and correlation coefficient comparison table.

Form of fitting function	Fitting formula	Correlation coefficient
Exponential function		0.998
		0.985
		0.995
		0.971
Power function		0.859
		0.822
		0.681
		0.764
Polynomial function		0.977
		0.977
		0.809
		0.967