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Basic Technical IVT Commonly tested

Void Space Backfill

noun

Pronunciation: /vɔɪd speɪs ˈbækˌfɪl/

The engineered process of filling underground cavities, adits, or pit voids created by mining operations with inert materials such as tailings, rock, or concrete to restore subsurface stability and prevent collapse. This practice is critical for preventing surface subsidence and reducing contamination pathways through abandoned mine workings.

Plain English

Filling empty underground spaces left behind by mining with rock or other stable material to prevent collapse.

Etymology & History

Origin languageEnglish, Middle English
Rootvoid (empty space) + back (again) + fill (to make full)
First recorded use1978
Usage frequencyCommon

Usage

"The reclamation plan required void space backfill of three major adits using compacted waste rock to eliminate subsidence risk in the surrounding community."

Style guide notes: Specify the material composition, placement method, and compaction specifications when describing void space backfill designs.

Also known as

underground backfilling cavity filling void filling

Contrasted with

open pit underground workings

Related Terms

Frequently Asked Questions

What materials are suitable for void space backfill?

Compacted waste rock, processed tailings, concrete grout, or bentonite slurry are approved depending on structural and environmental requirements.

Why is void space backfill necessary in mine closure?

It prevents surface subsidence, eliminates pathways for contamination migration, and improves long-term structural integrity of reclaimed land.

Why Test Candidates on This?

Evaluated in mine engineering and closure design competency assessments.

Required skill level: Mid

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