What type of lift should be used when backfilling an excavation?

When backfilling an excavation, utilizing a small lift while shading the ditch ensures that the material is compacted effectively without causing additional stress or potential instability to the excavation walls.

Small lifts allow for more controlled placement and compaction of the material, which helps prevent voids and enhances the overall stability of the backfilled area. When shading the ditch, it minimizes the impact of water infiltration which could lead to erosion or weakening of the backfill material. This method also keeps the earthwork manageable and allows operators to work safely within the confines of the excavation, reducing the risk of collapse.

Large lifts, while they cover more ground quickly, might not compact adequately and can lead to greater settlement issues over time. An at once lift would not allow for proper compaction, which is critical in maintaining the integrity of the excavation. Although a medium lift might seem more manageable than a large lift, not using shading can still risk destabilizing the backfill as water or environmental factors may affect the area negatively. Hence, the recommended practice of a small lift with shading balances effective compaction and safety in excavation work.