Anaerobic

Able to live and grow where there is no oxygen.

Angle of Repose

The angle which the sloping face of a bank of loose earth, gravel, or other material, makes with the horizontal.

Annular Filler

Material for grouting the annular space between the existing pipeline and the lining system.

Annular Space

The theoretical volume between the gauge cut and the outside radius of the jacking pipe times the length of the installation, equal to annulus x length of tunnel.

Annular Thickness

The radial distance between the excavated radius created by the gauge cutter and the outside radius of the jacking pipe. The radial distance is equal to the overcut (gauge cut) plus the shield cut.