Table 5 The measured and inversed geo-stresses.

From: Unloading damage evolution and rockburst risk assessment of Xuefengshan No.1 tunnel by combining multiple approaches

Testing points

Burial depth

Measured value (MPa)

Inversed value (MPa)

(m)

σx

σy

σz

σx

σy

σz

No.1

600 m

26.4

24.7

17.0

27.4

25.6

18.9

No.2

700 m

29.0

25.1

19.2

31.0

27.3

22.6

No.3

800 m

31.0

30.5

21.5

33.0

34.5

24.6