backfill

Backfill refers to the process of refilling an emptied space after excavation or removal. In civil engineering, backfilling surrounds foundations, pipes, or trenches with soil or other fill material to restore grade, provide support, and control drainage. The backfill material can be natural soil, engineered fill, gravel, crushed stone, or concrete in some cases.

Backfilling is typically performed in layers, with compaction to achieve a specified density and moisture content to minimize settlement and prevent damage to installed structures. Special precautions may be used around sensitive installations, such as pipelines, electrical ducts, or structural footings. Geotextiles or drainage layers may be employed to improve stability and water management.

In mining and waste disposal, backfill describes filling mined-out voids with rock, ore, tailings, or cemented paste to support underground workings, reduce subsidence, and improve environmental containment. Paste backfill combines tailings with cementitious binders to create a stable fill with high strength.

In data management and information technology, backfill is the process of supplying historical or previously unavailable data into a data store after a schema change, data migration, or the discovery of missing data. It is often performed in batches and may involve ETL procedures to ensure data completeness and consistency across time periods.