In excavation, what is a common method for compacting soil?

Compacting soil is an essential step in excavation and grading as it increases the soil's density, stability, and load-bearing capacity. Each of the methods listed—rolling, tamping, and vibrating—plays a vital role in this process, making the option indicating all of them correct.

Rolling involves using heavy machinery, such as a roller, to compress the soil surface. This method is effective for large areas and is particularly useful in preparing a smooth, stable surface for subsequent construction activities.

Tamping, on the other hand, focuses on small, localized areas. A tamper applies pressure through a mechanical or manual device, which is often employed in trench work or compacting around foundations, ensuring soil density in places that larger equipment may not reach efficiently.

Vibrating compaction uses vibrations to rearrange soil particles, allowing them to settle more closely together. This method is particularly effective for granular soils, as it helps to eliminate air gaps and improve the overall stability of the soil structure.

Since each method complements the others and can be used in different scenarios based on site requirements, the correct response is that all methods are commonly used for compaction in excavation processes.