Table 3 Minimum safety factor for temporary support shotcrete.

From: Support mechanical response analysis and surrounding rock pressure calculation method for a shallow buried super large section tunnel in weak surrounding rock

Construction step

Least safe location

Safety factor

Maximum bending moment (kN m)

Maximum axial force (kN)

3

I

6.21

47.4

− 1275.2

2

I

4.72

79.6

− 1677.4

4

II

2.14

186.5

− 1432.6

5

III

1.56

315.8

− 2951.4

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