What is the primary purpose of backfill in a trench for a water pipe installation?

• A. distribute surface loads
• B. absorb heat
• C. promote drainage
• D. insulate the pipe

Answer: (A)

Backfill around a water pipe mainly serves to distribute surface loads from above down into the surrounding soil, protecting the pipe from point loads and movement. By carefully compacting the material in layers, the backfill supports the trench walls and helps prevent settlement and displacement that could crush or misalign the pipe. While drainage, heat absorption, and insulation can be considerations in some projects, they are not the primary purpose of backfill in a standard trench for a water line. Drainage is addressed through proper trench grading and design, and insulation is not typically the main goal of backfill.