Grading in
civil engineering and landscape architectural construction is the work of ensuring a level base, or one with a specified
slope,[1] for a construction work such as a
foundation, the
base course for a
road or a
railway, or
landscape and
garden improvements, or surface drainage. The earthworks created for such a purpose are often called the sub-grade or finished contouring (see diagram).
Regrading
Regrading is the process of grading for raising and/or lowering the levels of land. Such a project can also be referred to as a regrade.
Regrading may be done on a small scale (as in preparation of a house site)[3] or on quite a large scale (as in major reconfiguration of the terrain of a city, such as the
Denny Regrade in
Seattle).[2]
Regrading is typically performed to make land more level (flatter), in which case it is sometimes called levelling.[4]) Levelling can have the consequence of making other nearby slopes steeper, and potentially unstable or prone to erosion.
Transportation
In the case of
gravel roads and
earthworks for certain purposes, grading forms not just the base but the cover and surface of the finished construction, and is often called finished grade.[5]
Process
After the existing conditions of the limit of work has been surveyed,
surveyors will set stakes in places that are to be regraded. These stakes have marks on them that either give a finished grade to the design of the project, or have CUT/FILL marks which specify how much dirt is to be added or subtracted. All grade marks are relative to site
benchmarks that have been established.[6] The regrading work is then often done using heavy machinery like
bulldozers and
excavators to roughly prepare an area, then a
grader is used for a finer finish.
^"Grade.1.". def. 2. Whitney, William Dwight, and Benjamin E. Smith. The Century dictionary and cyclopedia vol.3. New York: Century Co., 1901. 2589. Print.