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

Table 2

Statistical parameters of the random variables in example 2.

	Young’s modulus E (MPa)	Uniaxial compression strength σc (MPa)	Material constraints of the rock mass
			Original		Broken
			m	s	mr	sr
Distribution type	Normal	Normal	Normal	Normal	Normal	Normal
Mean value	1380	69	0.5	0.001	0.1	0
Standard deviation	138	6.9	0.05	0.0001	0.01	0.001