The Reliability-Based Design Optimization of considering Rock-Support Interaction for Rock Tunnels

Table 1

Statistical parameters of the random variables in example 1.

	Distribution type	Mean value	Standard deviation
Young’s modulus E (MPa)	Normal	1000	100
Poisson’s ratio μ	Normal	0.25	0.025
Cohesion c (MPa)	Normal	2.6	0.26
Friction angle φ (^o)	Normal	30	3