Improved Nonlinear Nishihara Shear Creep Model with Variable Parameters for Rock-Like Materials

Table 3

Model parameters under various shear stresses conditions.

Normal stress (MPa)	Shear stress (MPa)	(MPa)	(MPa)	(MPa·h)	(MPa·h)			τs(MPa)	ts (h)			Correlation coefficient R^2
0.78	1.23	0.8	11.60	44.866	—	0.985	3.861	—	—	—	—	0.998
	1.64	0.93	24.35	174.511	—	0.977	0.601	—	—	—	—	0.999
	2.05	1.01	22.36	137.981	—	0.996	1.096	—	—	—	—	0.997
	2.46	1.06	21.59	105.654	—	0.993	1.324	—	—	—	—	0.996
	2.87	1.08	19.67	196.583	—	0.991	0.703	—	—	—	—	0.999
1.56	1.68	1.06	17.58	260.98	—	0.999	0.435	—	—	—	—	0.999
	2.24	1.57	116.67	1212.06	—	0.977	0.628	—	—	—	—	0.999
	2.8	1.76	39.27	982.89	—	0.971	0.390	—	—	—	—	0.999
	3.36	0.74	7.10	3.9693	0.087	0.970	20.32	2.8	0.2634	−14.70	3.64	0.996
2.34	1.935	1.16	17.06	37.564	—	0.984	3.868	—	—	—	—	0.998
	2.58	1.26	32.09	1223.15	—	0.983	0.145	—	—	—	—	0.997
	3.87	1.48	42.2	603.86	—	0.990	0.787	—	—	—	—	0.999
	4.515	1.55	17.94	291.13	—	0.986	0.461	—	—	—	—	0.996
	5.16	1.57	9.52	245.49	—	0.977	0.192	—	—	—	—	0.998
3.12	2.199	0.54	22.15	212.33	—	0.993	1.894	—	—	—	—	0.999
	2.99	0.65	22.46	370.49	—	0.979	0.246	—	—	—	—	0.998
	4.398	0.86	25.86	287.12	—	0.997	0.769	—	—	—	—	0.997
	5.131	0.97	21.73	186.73	—	0.999	1.678	—	—	—	—	0.999
	5.864	1.06	21.76	290.39	—	0.999	0.821	—	—	—	—	0.998