Fatigue Life Characteristics of Segmental Lining Structure for the Shallow Buried Metro Tunnel under the Dynamic Load of a High-Speed Railway

Table 1

The S-N formula of the concrete fatigue life with different types and stress conditions.

No.	Species	formula	Condition	Author
1	C25		Splitting tensile	Tepfers
2	C25		Uniaxial	Saito
3	C50		Uniaxial, dry	Cornelissen
4	C50		Uniaxial, humid	Cornelissen
5	C50		Splitting tensile	Zhao
6	C50		Axis tensile	Zhao
7	C50	,	Bending tensile	Zhao
8	C25		Splitting tensile	Zhao
9	C30		Uniaxial	Song
10	C30	,	Uniaxial	Song

Note. is the fatigue life of the concrete, is the maximum stress of the specimen (MPa), is the minimum stress (MPa), and is the tensile strength of the concrete (MPa).