Table 1 Q classification results.

From: Failure control of large-scale exposed tunnels under the combined effects of excavation damage and dynamic disturbance at a depth of 1240 m

Test location

M1

M2

M3

M4

RQD

29.45

33.66

20.51

24.12

\({J}_{n}\)

2

2

2

2

\({J}_{r}\)

1

1

2

2

\({J}_{a}\)

4

5

5

6

\({J}_{w}\)

1

1

1

1

\(SRF\)

2

2

3

3

\(Q\)

0.69

0.63

0.09

0.08

grade

IV

IV

V

V