Research on Construction Methods for Ultralarge Y-Shaped Tunnel Sections

Table 5

Safety factor of secondary lining of tunnel.

Working condition	Position	Arch roof	Right arch waist	Right arch foot	Arch bottom	Left arch foot	Left arch waist
Working condition 1	Bending moment(kN^.m)	−20.92	−200.25	−170.70	−10.86	−365.68	−341.76
	Axial force (kN)	−1214.11	−5687.47	−2524.69	−710.27	−5789.84	−7420.80
	Factor of safety	16.84	3.39	6.83	28.97	3.01	2.51
Working condition 2	Bending moment (kN^.m)	−19.18	−198.63	−183.21	−12.24	−348.82	−339.57
	Axial force (kN)	−1089.13	−5528.96	−2675.42	−722.35	−5610.71	−7258.60
	Factor of safety	18.75	3.48	6.42	28.33	3.13	2.56