Tremie pipe or line is a device, usually a small diameter pipe or hose, that performs the following functions...

• A. Delivers drilling mud to surface
• B. Provides drainage for the borehole
• C. Allows pressure grouting from the bottom without air pockets
• D. Allows air pockets in the grout

Answer: (C)

Tremie placement is about getting grout or concrete to the bottom of a borehole or underwater space without trapping air or water in the mix. The tremie pipe acts as a conduit that stays submerged as grout is pumped down and flows out at the bottom. Because the end of the tremie remains below the grout surface, water from the surrounding environment is pushed away and the grout forms a continuous column from the bottom up. This prevents air pockets and segregation, producing a solid, watertight fill. The function described captures this bottom-up, air-free placement. The other options describe functions not associated with tremies: handling drilling mud, providing drainage, or allowing air pockets—which would undermine the integrity of the grout.