Experimental Evaluation of the Influences of Water on the Fracture Toughness of Mudstones with Bedding

Table 1

Fracture parameters (Y_I, Y_II, ) for the SCB specimens with (α/R = 0.35 and S/R = 0.50) and for various crack inclination angles (according to Ayatollahi and Aliha [34]).

β (°)	YI	YII		M^e
0	2.787	0	−0.6972	1
5	2.748	0.249	−0.5918	0.9425
15	2.397	0.671	0.0142	0.8262
30	1.461	0.978	1.4875	0.6245
45	0.518	0.871	2.7143	0.3416
54	0	0.659	3.0830	0