The downward movement of water from the surface into the soil.

Defined as an "underlying foundation or basic framework". Has come to mean a diverse collection of constructed facilities and associated services that support industry, commerce and everyday living

The cost of establishing a facility and putting it into initial operation. See also construction cost

Relatively short-term tunnel or shaft support installed for stability and safety during construction operations, with elements generally left in place and incorporated into the final linig. Initial support is often referred to as primary support.

This phase of construction covers preparation for immersion, the immersion, foundation preparation, backfilling, and completion of the interior works

All items including men, equipment, and supplies required to perform a function.

The interior curve of an arch, as of a tunnel lining.

A value of an amenity or object that is independent of whether there is a financial market for the amenity or object. Such values depend on community or individual attitudes

The lowest section of a tunnel, i.e., the floor. On a circular configuration, it is approximately the bottom 90 degree of the arc of the tunnel. On a square-bottom configuration, it is the bottom of the tunnel.

Process in which the invert of a tunnel is poured separately. See arch pour.

When tunnel ribs tend to move inward at the tunnel invert, compression struts are installed across the invert to resist this movement. These are the invert struts.

Expenditure now, or in the near future, in order to obtain benefits spread over time. Also means the amount of the expenses.

See division of communities

Light, hand-held percussion drill.

A ducted propeller, usually mounted adjacent to or above the traffic, that helps to maintain air velocity within that cell.

The process of applying water or air under pressure to remove debris or laitance from structural surfaces.

Horizontal support for drifter drills bolted to a jumbo. These arms allow mechanical positioning of the drill at the tunnel face. Some jibs allow rotation of the drills so that side holes and lifters can be drilled closer to the final grade.

Horizontal support for drifter drills bolted to a jumbo. These arms allow mechanical positioning for the drill at the tunnel face. Some jibs allow rotation of the drill so that side holes lifters can be drilled closer to the final grade.

Manual or hydraulic rail bender.

In rock, a naturally occuring fracture or parting along which there has been no visible movement parallel to the fracture plane or surface.