Table A-1 <br /> <br />Terminology Used to Describe Soil <br /> <br />2 of 2 <br />Soil Descriptions <br />C <br />oarse - Grained Soils (less than 50% fines) <br />Coarse-grained soil descriptions, i.e., SAND or GRAVEL, are based on the portion of materials passing a 3-inch (75mm) sieve. <br />Coarse-grained soil group symbols are applied in accordance with ASTM D2488-06 based on the degree of grading, or <br />distribution of grain sizes of the soil. For example, well-graded sand containing a wide range of grain sizes is designated SW; <br />poorly graded gravel, GP, contains high percentages of only certain grain sizes. Terms applied to grain sizes follow. <br /> Particle Diameter <br />Material NAME <br />Inches Millimeters <br />SAND (SW or SP) 0.003 0.19 0.075 4.8 <br />GRAVEL (GW or GP) 0.19 3 4.8 75 <br />Additional Constituents: <br />Cobble 3 12 75 300 <br />Boulder 12 120 300 3050 <br />The primary soil type is capitalized, and the fines content in the soil are described as indicated by the following examples. <br />Percentages are based on estimating amounts of fines, sand, and gravel to the nearest 5 percent. Other soil mixtures will <br />have similar descriptive names. <br />Example: Coarse-Grained Soil Descriptions with Fines <br />>5% to < 15% fines (Dual Symbols) 15% to < 50% fines <br />Well graded GRAVEL with silt: GW-GM Silty GRAVEL: GM <br />Poorly graded SAND with clay: SP-SC Silty SAND: SM <br />Additional descriptive terminology applied to coarse-grained soils follow. <br />Example: Coarse-Grained Soil Descriptions with Other Coarse-Grained Constituents <br />Coarse-Grained Soil Containing Secondary Constituents <br />With sand or with gravel 15% sand or gravel <br />With cobbles; with boulders Any amount of cobbles or boulders. <br />Cobble and boulder deposits may include a description of the matrix soils, as defined above. <br />Relative Density terms are applied to granular, non-plastic soils based on direct measure or correlation to the Standard <br />Penetration Test N-value as determined by ASTM D1586-84. <br />Relative Density Term SPT N-value <br />Very loose 0 4 <br />Loose 5 10 <br />Medium dense 11 30 <br />Dense 31 50 <br />Very dense > 50 <br /> <br />