Which step helps ensure that backfilled trench features do not settle over time?

Which step helps ensure that backfilled trench features do not settle over time?

• A. Compaction testing
• B. Visual inspection
• C. Dust control training
• D. Final painting

Answer: (A)

Backfill settlement is controlled by getting the soil to the proper density and proving it with tests. When trench backfill is placed, each lift must be compacted to a target density, usually a percentage of the soil’s maximum dry density, and the moisture content should be suitable for compaction. Compaction testing provides objective data that the fill has reached that density and is compacted uniformly, reducing voids that would settle under load over time. If tests show insufficient density, the material is re-compacted until it meets the spec. Visual checks can’t reliably detect density or voids, while dust control training and final painting don’t affect the soil’s ability to support loads.

Backfill settlement is controlled by getting the soil to the proper density and proving it with tests. When trench backfill is placed, each lift must be compacted to a target density, usually a percentage of the soil’s maximum dry density, and the moisture content should be suitable for compaction. Compaction testing provides objective data that the fill has reached that density and is compacted uniformly, reducing voids that would settle under load over time. If tests show insufficient density, the material is re-compacted until it meets the spec. Visual checks can’t reliably detect density or voids, while dust control training and final painting don’t affect the soil’s ability to support loads.