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Soil compaction is a vital part of the construction process. It is used for support of structural entities such as building foundations, roadways, walkways, and earth retaining structures to name a few. For a given soil type certain properties may deem it more or less desirable to perform adequately for a particular circumstance.
Soil bulk density, when determined at standardized moisture conditions, is an estimate of soil compaction. [3] Soil porosity consists of the void part of the soil volume and is occupied by gases or water. Soil consistency is the ability of soil materials to stick together. Soil temperature and colour are self-defining.
Soil compaction, also known as soil structure degradation, is the increase of bulk density or decrease in porosity of soil due to externally or internally applied loads. [1] Compaction can adversely affect nearly all physical, chemical and biological properties and functions of soil . [ 2 ]
The original Proctor test, ASTM D698 / AASHTO T99, uses a 4-inch-diameter (100 mm) by 4.584-inch-high (116.4 mm) mold which holds 1/30 cubic feet of soil, and calls for compaction of three separate lifts of soil using 25 blows by a 5.5 lb hammer falling 12 inches, for a compactive effort of 12,375 ft-lbf/ft 3.
soil composition (basic soil material): mineralogy, grain size and grain size distribution, shape of particles, pore fluid type and content, ions on grain and in pore fluid. state (initial): Defined by the initial void ratio, effective normal stress and shear stress (stress history). State can be describd by terms such as: loose, dense ...
Zone tillage is a form of modified deep tillage in which only narrow strips are tilled, leaving soil in between the rows untilled. This type of tillage agitates the soil to help reduce soil compaction problems and to improve internal soil drainage. [12] It is designed to only disrupt the soil in a narrow strip directly below the crop row.
Dynamic compaction is a method that is used to increase the density of soils when certain subsurface constraints make other methods of soil compaction inappropriate. The process involves dropping a heavy weight repeatedly on the ground at regularly spaced points, usually laid out in a systematic fashion such as a grid.
Preconsolidation pressure is the maximum effective vertical overburden stress that a particular soil sample has sustained in the past. [1] This quantity is important in geotechnical engineering, particularly for finding the expected settlement of foundations and embankments.