Conveyor Tunnel In A Coal Mine

We install concrete floors, spray shotcrete on exposed roof and walls (ribs), place steel sets, and then backfill over the arches for mine conveyor transfer points. This work can be more challenging due to working around moving conveyors and in confined space. The other challenges are regularly presented by the extreme pumping distances for concrete and backfill-often as much as 5,000 LF from the surface.

The coal conveyor is on the left

Arch beams are not painted

Miners wash down the concrete floor to keep it clean

Arches can be installed in lower areas

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

Train Tunnel In Ohio

These photos are from a train tunnel rehabilitation in Ohio. The arch sets and steel lagging (between the steel beams) are painted. Arches are connected via "struts" which bolt each arch set to the next arch.

Gould Tunnel Arches and Concrete Footers

In Process

Lagging On Inside of Beams or Outside

Optional Wall Anchors

Camber Corp Arch Photos

Here are various steel arch set photos from Camber Corporation. Camber is the preferred supplier of steel arch sets and accessories for R G Johnson.

Arches installed prior to covering with dirt for mine decline

Painted arches and lagging

Galvanized lagging

Painted arches and lagging

High and wide arches

In front of a highwall