Mine Decline Tunnel

Galvanized steel arches and lagging highlight this tunnel. The vertical posts were all cut to length in the field to match the uneven floor elevations. The customer then poured a concrete floor around the beams. Cellular concrete backfill with 100 PSI compressive strength was then pumped between the arches and the roof and ribs. Backfill provided  full perimeter contact between the arches and the roof and ribs to improve rock loading on the structure.

Arches were installed at the end of the concrete tunnel in the rock section

The angles attached to the vertical beams were used to support cross beams. An elevated floor deck was poured later which split the tunnel into a top and bottom compartment.

The access opening at the top of the arch is closed as the backfill goes over the arch