Heaving

Process in which the ground in front of a pipe jack may be displaced forward and upward causing a lifting of the ground surface.

Height of Cover (HC)

Distance from crown of a culvert or conduit to the finished road surface, or ground surface, or the base of the rail.

Helicoid

A section of auger flight.

Hex Drive

See Drive ChuckThe female hex connector located within the casing pusher..

High Density Polyethylene

A plastic resin made by the copolymerization of ethylene and a small amount of another hydrocarbon. The resulting base resin density, before additives or pigments, is greater than 0.941 gins/cc.