A Copula-Based Method for Estimating Shear Strength Parameters of Rock Mass

Table 2

Correlation coefficients of the rock mass quality indices and the shear strength.

Variables	Pearson	Spearman	Kendall
RQD-f	0.307	0.386	0.303
RBI-f	0.241	0.376	0.303
Q-f	0.550	0.656	0.545
RQD-c	−0.517	−0.397	−0.333
RBI-c	−0.573	−0.635	−0.515
Q-c	−0.563	−0.517	−0.485