👉 A backfill is a type of soil preparation method used to fill in gaps or voids between existing soil layers. It involves using soil, sand, or other materials to cover and stabilize the surface of a surface such as a road, highway, or pavement. In general, the process involves applying a mixture of soil, sand, or gravel over the top of the existing layer. The goal is to create a smooth surface that will allow for better drainage and prevent soil erosion. This can be done
