By the owner of the work as being fully complete in accordance with the contract documents.

Adapter Ring

In microtunneling, a fabricated ring, usually made from steel, that is mounted on the first pipe of the pipe string. This ring is intended to transfer the jacking force from the MTBM’s bearing area to the jacking pipe and to create a waterproof seal between the machine and the spigot of the first joint.


Written or graphic instruments issued prior to the execution of the agreement, which modify or interpret the contract documents, drawings and specifications, by addition, deletions, clarifications, or corrections.


A substance added in a small amount, usually to a fluid, for a special purpose such as to reduce friction, corrosion, etc.


Ingredients added during mixing; often in construction to aid workability of concrete, mortar or grout.