Study on the Large Deformation Characteristics and Disaster Mechanism of a Thin-Layer Soft-Rock Tunnel

Table 7

Mechanical properties of the carbonaceous slate.

Lithology	Rock mass parameters						Structural plane parameters
	Density (kg/m^3)	K (GPa)	G (GPa)	C^b (MPa)	φ^b	(MPa)	K^n (GPa)	k^s (GPa)	C^j (MPa)	φ^j	(MPa)
Carbonaceous slate in the natural state	2500	0.44	0.25	1.7	22	0.6	30.21	12.08	3.75	29	3.45
Carbonaceous slate in the saturated state	2500	0.24	0.092	0.94	20	0.3	11.17	4.45	2.91	20	1.66

Note. φ: internal friction angle; σ_t: tensile strength; C: cohesion.