Which term describes the load that decreases as trench width increases?

• A. Trench Load
• B. Pipe Bedding
• C. Manhole Safety
• D. Pipe Deflection

Answer: (A)

Understanding how trench width affects the load on a buried pipe comes down to how soil pressure is transmitted. The term that describes the load on the pipe from the surrounding backfill is trench load. When the trench is narrow, the backfill weight concentrates more directly on the pipe, so the load is higher. As the trench becomes wider, soil arching and pressure distribution to the trench walls reduce the vertical pressure directly on the pipe, so the load on the pipe decreases.

Pipe bedding is the layer of material under the pipe that helps support it, but it’s not describing how load changes with trench width. Manhole safety relates to safeguarding workers and equipment, not the load on a pipe due to trench dimensions. Pipe deflection is the pipe’s bending or deformation under load, not the load itself.