What is done after portions of backfill are placed in the trenches?

• A. Tamping
• B. Grading
• C. Joints are pressure tested
• D. Wire is placed across portions of the backfill

Answer: (A)

When backfilling trenches, compacting the soil after each portion is placed is essential. Tamping pushes the soil grains closer together, expelling air pockets and bringing the fill to the proper density. This creates a stable surround for the pipe, helps prevent future settlement or movement, and maintains the intended trench grade and load-bearing capacity. Proper tamping also minimizes voids that could later settle and cause issues above the trench.

Grading is usually done after backfilling to restore the surface level, joints are typically pressure-tested before or during installation to ensure pipe integrity, and placing wire across backfill isn’t a standard step in this process.