Uppfyllning

Uppfyllning is a term used in construction, geotechnics and mining to describe the material and the process of filling a void or raising the ground level. It covers both the chosen fill material and the work of distributing and compacting it to achieve desired geotechnical properties. The concept is applied in a wide range of contexts, including road and rail construction, building basements and foundations, trench backfilling, retaining walls, landfill operations, and backfilling of mined workings.

Fill materials can vary widely and include natural soils such as clay, silt, sand and gravel, crushed rock, or mixtures tailored for specific properties. In some cases recycled or stabilised materials are used, provided they meet requirements for strength, permeability, drainage and chemical compatibility. The fill is placed in layers and compacted to achieve target density and settlement characteristics. Field and laboratory tests, such as density measurements and moisture control, are commonly employed to verify performance.

Key design considerations include potential settlement and differential movement, drainage and pore-water pressures, frost susceptibility, permeability, and chemical interactions with existing soils or structures. Proper compaction and grading help minimize voids, reduce erosion risk, and ensure stability for adjacent structures. In mining contexts, uppfyllning refers to backfilling excavated voids with waste rock, tailings or other materials to stabilise openings and reclaim space.

Standards and project specifications govern material quality, compaction criteria, testing, and documentation. The term is used in Swedish technical language to describe both the material and the process of filling or backfilling in construction, geotechnical engineering and mining.