Table 4 Support optimization plan.

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

Number

Scheme diagram

descriptive

Support parameters

I

mesh-bolt-cable-shotcrete

mesh: mesh 60 mm × 60 mm, mesh angle 90°

bolt: 10 bolts, length 2 m, yow line space 1 m × 1 m (100 kN)

cable: 5 cables, length 8 m, yow line space1m × 1 m(200 kN, 45°)

shotcrete: thickness 0.1 m

II

mesh-bolt-shotcrete

mesh: mesh 60 mm × 60 mm, mesh angle 90°

bolt: 11 bolts, length 2 m, yow line space 1 m × 1 m (100 kN)

shotcrete: thickness 0.1 m

III

mesh-bolt-cable-shotcrete

mesh: mesh 60 mm × 60 mm, mesh angle 90°

bolt: 10 bolts, length 2 m, yow line space 1 m × 1 m(100 kN)

cable: 5 cables, length 6 m, yow line space1m × 1 m(200 kN, 45°)

shotcrete: thickness 0.15 m

IV

mesh-bolt-cable-shotcrete

mesh: mesh 60 mm × 60 mm, mesh angle 90°

bolt: 10 bolts, length 2 m, yow line space 1 m × 1 m(100 kN)

cable: 3 cables, length 8 m, yow line space1m × 1 m(200 kN, 15°)

shotcrete: thickness 0.1 m