Stress Monitoring for Anchor Rods System in Subway Tunnel Using FBG Technology

Table 2

Parameters of wall rock and tunnel lining.

Name	Specific gravity	Elasticity modulus/GPa	Poisson’s ratio	Cohesion/kPa	Internal frictional angle/°
Wall rock	1.78	0.027	0.35	34	26
Wall rock	2.5	30	0.20	2420	54
Anchor rod	5.23	100	0.25	Diameter: 80 mm