A Simple Three-Dimensional Failure Criterion for Jointed Rock Masses under True Triaxial Compression

Table 1

True triaxial compression strength of experimental and predicted results of jointed marble (data from [9]; here, compressive stress is considered positive).

σ3 (MPa)	σ2 (MPa)	σ1exp (MPa), test data at joint inclination angle β (°)						σ1cal (MPa), calculated data at joint inclination angle β (°)
		0	20	40	60	80	90	0	20	40	60	80	90
0	0	158.59	100.79	73.76	77.57	112.21	141.07	146.23	110.16	81.81	84.31	118.00	144.63
10	60	279.94	296.43	272.40	240.12	242.96	258.62	276.72	254.21	220.28	202.30	224.88	240.92
30	60	332.25	361.55	330.96	305.12	338.63	357.16	354.39	339.66	319.75	307.68	300.75	304.06
30	90	409.76	387.18	363.12	337.69	311.01	297.24	395.24	384.82	363.43	337.62	330.11	331.26
30	120	377.51	366.23	350.79	333.50	316.97	309.78	427.12	421.00	397.62	357.13	350.11	349.71
K	_	_	_	_	_	_	0.7196	0.7221	0.7011	0.6651	0.7084	0.7272
a	_	_	_	_	_	_	22.64	23.38	5.58	12.21	23.07	25.38
b	_	_	_	_	_	_	17.98	19.34	4.84	10.37	17.15	17.24
d	_	_	_	_	_	_	40.96	30.27	17.54	20.26	38.97	55.32