In the context of load factors, what does 'swell' refer to?

In the context of load factors, 'swell' specifically refers to the increase in volume that occurs when soil or other materials are excavated. When earth materials are removed from their in-situ position, they often expand or 'swell' due to the reduction of confinement pressure. This expansion is commonly observed in various types of soils, such as clay, where the material can absorb moisture and lead to a significant increase in volume compared to its original compacted form.

Understanding swell is crucial for contractors and engineers as it can affect the calculations related to load-bearing capacity and the overall stability of the site or construction project. Accurate estimates of swell are essential for determining how much material will be needed for backfilling, grading, or other construction activities. This knowledge helps in ensuring proper planning and execution of construction tasks while avoiding potential complications related to volume changes in materials.

The other options pertain to different aspects of materials and construction, but they do not specifically capture the meaning of 'swell' in the context of load factors.