Mechanical and Deformation Characteristics and Optimization of Support Parameters for Superlarge-Span Tunnel: A Case Study from Laohushan Tunnel

Table 6

Primary support internal force and material safety factor.

Number	Position	Shotcrete axial force (kN)	Axial force of steel rib (kN)	Steel rib bending moment (kN·m)	Shotcrete safety factor	Steel rib tensile safety factor	Steel rib compression safety factor
0	Vault	506.9	141.7	−7.9	8.3	12.3	4.7
1	Vault deviated left 30°	1421.0	397.1	−4.2	3.2		3.8
2	Vault deviated right 30°	829.6	231.9	−2.2	5.2		6.8
3	Left hance 60°	1787.5	499.6	−1.2	2.6	4.8	3.9
4	Right hance 60°	1042.7	291.4	−8.0	4.2	74.7	3.5
5	Left skewback	1304.4	364.6	−3.3	3.5		4.3
6	Right skewback	760.4	212.5	−12.0	5.6	8.0	3.1
7	Left side wall	183.7	51.3	5.4	22.1	12.9	8.0
8	Right side wall	15.6	4.4	−0.1	256.6		275.8