What is required when filling or backfilling with soil that has been excavated by a backhoe?

When filling or backfilling with soil that has been excavated by a backhoe, compaction is crucial for several reasons. Proper compaction of the soil helps to eliminate air pockets, which can lead to settling in the future. This settling can create voids and instability under structures or surfaces placed on top of the backfilled area. Compacted soil provides a stable, durable base which is essential for supporting the weight of any structures, roadways, or landscaping that may be placed over it.

In addition, compacted soils exhibit improved load-bearing characteristics, enhancing their ability to withstand environmental factors over time. Proper techniques such as using a plate compactor, vibratory roller, or a hand tamper can be employed to ensure that the soil reaches an adequate level of compaction.

The other options do not recognize the importance of soil stability. Leaving the soil loose, not requiring additional work, or assuming that the soil will become denser on its own ignores the physical changes that occur to soil texture and structure during excavation, which necessitate the need for deliberate compaction processes to ensure the integrity and longevity of the filled area.