Subgrade compaction is earthwork. According to relevant public information, the classification of earthwork includes site leveling, foundation pit (trench) excavation, foundation pit (trench) backfilling, large-scale earthwork excavation in underground engineering and subgrade construction. Subgrade construction refers to the roads inside and outside the site where the construction project is located, as well as special roads and railways, which need to build subgrade. Subgrade excavation is called cutting and filling is called embankment.