Glossary of Trenchless Terms

The theoretical area between the gauge cut and the pipe OD equal to (? x (Gauge Cut OD2 – Pipe OD2)/4). It is the combined area created by the overcut and the shield cut.

The electrode at which oxidation or corrosion occurs; opposite of cathode.

American National Standards Institute, Inc.

A value of tensile strength used for comparative purpose that is determined by tensile testing pipe rings in accordance with ASTM D 2290. This differs from true tensile strength of the material due to a bending moment induced by the change in contour of the ring as it is tested. Apparent tensile strength may be at yield, rupture or both.

The apparent tensile strength calculated for the yield condition.

The form furnished by the engineer which is to be used by the contractor in requesting progress payments, and an affidavit of the contractor that progress payments theretofore received from the owner on account of the work been applied by the contractor to discharge in full all of the contractor’s obligations stated in prior applications for payment.

Accept as satisfactory.

Large pipe or conduit to convey water from distant source.

Pertaining to water; an aqueous solution is a water solution.

GIS program for sewer data collection and display.

A paved surface, serving as an entry area basement or subsurface portion of a building, which is provided with some form of drainage that may be connected to a sewer line.

Designation of a main road system with many connecting minor roads.

After a sewer has been constructed it is checked for conformance to plan specifications. The actual measurements (As-Built) are written on the plan near the original plan measurements. The As-Built measurements are often set-off in a box to differentiate the two measurements. Measurements are of the elevations for the manhole top cover, manhole invert(s) and ground level, for percent grade, etc.

American Society of Civil Engineers

A valuable resource.

American Society of Testing and Materials; technical organization formed for the development of standards on characteristics and performance of materials, products, systems and services, and the promotion of related knowledge.

A flighted drive tube having hex couplings at each end, to transmit torque to the cutting head and transfer spoil back to the machine.

A technique for forming a bore from a jacking or drive shaft to a receiving shaft by means of a rotating auger with cutting tools. The casings are jacked forward sequentially in a cyclic process while the auger is turned. Spoils are removed back to the drive shaft by helically wound auger flights rotating in the steel casing. The equipment may have limited guidance and steering capability.

A machine used to drill earth horizontally by means of a cutting head and auger or other functionally similar device. The machine may be either cradle or track type.

A type of microtunnel boring machine that uses auger flights to remove the spoils through a separate, smaller casing placed through the jacking pipe.

Tunnel boring machine in which the excavated soil is removed to the drive shaft by auger flights passing through the product pipeline pushed in behind the TBM.

An automated spoil transportation system that conveys.

Water necessary for the performance of work, which may be taken from the fire hydrant nearest the worksite, given conditions of traffic and terrain which are compatible with the use of the hydrant for performance of work.

American Water Works Association

A cutting head attached to the leading end of a drill string to enlarge the pilot bore during a pull-back operation to enable the carrier or sleeve or casing to be installed in.