Unified Soil Classification System

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Unified soil Classification System : Field Method1Department of Sustainable Natural ResourcesSOIL SURVEY STANDARD TEST METHODUNIFIED soil Classification System : FIELD METHOD ABBREVIATED NAMEUSCSTEST NUMBERP13TEST METHOD TYPEBVERSION NUMBER2SCOPEThis test method describes the engineering properties of a soil based on the size of theparticles, the amounts of the various sizes and the characteristics of the very fine grains. It canbe carried out by either field examination or laboratory APPARATUSSieves, 75 mm, mm (ASTM No 4), mm (ASTM No 10), mm aperture (ASTM No40). Unified soil Classification System : Field Method2PROCEDUREField Classification Technique for Coarse-Grained Soils1. Take a representative sample of soil (excluding particles >75 mm) (see Note 1) andclassify the soil as coarse-grained or fine-grained by estimating whether 50% by weight, ofthe particles can be seen individually by the naked eye. Soils containing >50% of particlesthat can be seen are coarse-grained soils; soils containing <50% of particles smaller thanthe eye can see are fine-grained soils.

plasticity characteristics. For this substantial number of soils, boundary classifications are used i.e. the groups symbols most nearly describing the soil are connected by a hyphen, such as GW-GC. Proper boundary classification of a soil near the borderline between coarse-grained and

  Soil, Characteristics