Research on Shield Tunnelling Parameters Correlation in Composite Strata

Table 1

Physical and mechanical parameters of rock and soil mass.

Geotechnical layer	Density (g/cm^3)	Natural water content (%)	Specific gravity	Porosity ratio	Direct fast shear test		Modulus of deformation (MPa)	Permeability coefficient (m/d)	Thermal conductivity (w/m·k)	Coefficient of rock or soil foundation (MPa/m)		Stratigraphic resistance factor (MN/m^3)	Poisson’s ratio	Rock quality designation, RQD (%)
					Cohesion (kPa)	Angle of internal friction (°)				Horizontal	Vertical
Vegetative fill	1.84	26.2	2.73	0.871	12	10	—	5	—	15	10	5	—	—
Clay	1.93	26.00	2.74	0.787	30	12	18	0.004	1.97	33	30	11	0.36	—
Medium sand	1.97	—	2.64	—	1	31	29	40	2.28	26	24	14	0.30	—
Coarse sand	1.98	—	2.64	—	1	34	32	80	2.23	30	26	16	0.29	—
Gravelly sand	2.00	—	2.63	—	1	36	33	100	2.06	35	30	20	0.29	—
Strongly weathered muddy siltstone	2.02	—	—	—	40	25	80	0.8	1.60	100	100	40	0.32	—
Medium-weathered muddy siltstone	2.25	—	—	—	350	32	—	0.1	2.06	220	220	60	0.27	40–90