Term used in the United States for the temporary end bulkhead.

Miner's term for gases other than air which might be encoutered in an underground excavation.

An unplanned event which exposed persons to danger but which did not cause personal injury or acute ill health.

Shift that extends from 8:00 am to 4:00 pm. See swing shift.

Decibel -- a measure of sound level and used as a measure of noise pollution. dBA indicates a weighting of the measurements to increase the importance of low frequency sounds

Basins used for decanting of drilling bentonite mud.

A measure of sound level. Used as a measure of noise pollution

A person who makes decisions. The term usually refers to people making decisions on behalf of businesses or government.

A shaft of relatively (but not formally defined) great depth, usually associated with mines and underground waste storage and less often with civil engineering projects which are relatively shallow.

A device for precisely measuring the relative rotation of adjacent line segments along a common axis. The products of the sine of the relative rotation angle and length of line segment are summed by means of double integration techniques to obtain a displacement profile.

A change of shape of a structure or part of a structure or the ground. Usually refers to the change in shape with respect to load and time of the inner profile of the tunnel.

An enforced wait in an activity. Pertains to value-of-time studies

Exploders used in the tunnel face, that have delay provisions resulting in the charges' firing in rotation. Delay caps are used so that the rock will be exploded into an area into which it can expand.

Permission required to demolish buildings within areas with development plans. Permission is obtained by Building Committee

A method of conveyance of wet mix from the shotcrete machine by which the wet mix is conveyed through the delivery line without compressed air.

Equipment used for treating and eliminating sand of bentonite mud.

The information required to carry out engineering works

Zoning plans used to regulate land use and the construction of buildings and facilities in greater detail. DPs are binding for private and public. DPs are adopted by the City Coucil after a legal process

Inclined short drill holes near the center of the tunnel face, so arranged that when the first shots are exploded in the round, a diamond-shaped wedge of rock is removed, which allows relief for the remaining rock when the delay exploders set off the charges in the other drill holes.

Wall built by concreting within a deep and narrow trench the sides of which are held in place by a thixotropic slurry.