Numerical Tests Research on Mechanical Parameters of Rockmass considering Structural Plane Combination Characteristics

Table 3

Fracture stresses of rockmass with different dip angles and spacing when the confining pressure is 1.5 MPa (a represents side length).

Geometry characteristics of structure plane		Fracture stress values under confining pressures 1.5 MPa/MPa
Type	Dip angle (°)/space (m)	H = 0.108 m	H = 0.108 m	a = 0.5 m	a = 1 m	a = 2 m	a = 3 m	a = 4 m	a = 5 m	a = 6 m
Single joint	30/0.1		25.10	17.50	19.30	21.90	23.60	23.20	20.40	24.10
	45/0.1		9.99	3.30	2.50	2.62	3.10	1.68	2.61	2.87
	60/0.1		6.47	3.35	2.62	2.32	2.77	2.92	2.86	2.72
	30/0.3		25.10	20.60	18.70	20.90	22.30	20.80	21.00	22.80
	45/0.3		9.90	4.12	2.71	2.80	3.28	2.47	1.86	2.28
	60/0.3		6.50	6.47	4.20	3.05	3.12	2.71	2.46	3.42
	30/0.6		25.10	21.10	19.50	23.90	21.20	21.40	19.90	20.70
	45/0.6		9.97	3.70	3.16	4.21	4.27	2.43	2.12	2.31
	60/0.6		6.47	8.63	6.31	4.32	3.28	2.77	2.90	2.80
	30/1.0		25.10	21.10	20.10	20.50	23.10	20.40	19.70	22.00
	45/1.0	33.5 (no joint)	9.97	3.71	2.88	3.89	4.08	3.46	2.61	2.54
	60/1.0		6.57	8.64	7.62	4.67	4.74	2.98	3.05	2.87
X-shaped joint	30/0.1–45/0.1		9.16	4.15	4.12	3.95	3.38	3.57	3.78	3.79
	45/0.1–60/0.1		7.17	3.02	2.42	2.29	2.15	2.25	2.19	1.94
	60/0.1–30/0.1		7.34	2.87	2.71	2.27	2.29	2.27	2.32	2.35
	30/0.5–45/0.5		9.36	5.43	5.41	3.81	3.71	3.93	4.55	5.18
	45/0.5–60/0.5		7.16	3.78	2.61	3.15	2.96	2.53	2.54	2.31
	60/0.5–30/0.5		7.34	9.72	4.35	4.80	2.92	2.51	2.92	2.67
	30/1.0–45/1.0		9.35	6.20	5.20	4.90	4.31	4.38	4.41	4.58
	45/1.0–60/1.0		7.16	3.75	2.64	3.83	3.78	3.88	2.57	2.31
	60/1.0–30/1.0		6.99	9.72	9.30	5.70	5.00	3.55	3.56	2.80