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Andrie Street Improvements <br />Ramsey, Minnesota <br />NTI Project No. 15.61197.100 <br />Classification of Soils for Engineering Purposes <br />ASTM Designation D-2487 and D 2488 (Unified Soil Classification System) <br />Major Divisions Group Typical Names Classification Criteria <br />Symbols <br />Course Grained Soils <br />More than 50% retained on No. 200 sieve' <br />Gravels <br />50% or more of coarse fraction <br />retained on No 4 sieve <br />Clean Gravels <br />Well –graded <br />gravels and <br />GW gravel -sand <br />mixtures, fines.es.little or <br />noCz <br />fines. <br />Classification on basis of percentage of fines. <br />Less than 5% passing No. 200 Sieve: GW, GP, SW, SP <br />More than 12% passing No. 200 Sieve: GM, GC, SM, SC <br />From 5% to 12% passing No. 200 Sieve: Borderline Classification <br />raniiirinn ilea of rli ial cvmhnlc <br />Cu = D60 / Dto greater than 4. <br />= (D30)2 / (Dio x D60) between 1 & 3. <br />Poorly graded <br />gravels and <br />GP gravel -sand <br />mixtures, little or <br />no fines. <br />Not meeting both criteria for GW materials. <br />Gravels with <br />Fines <br />Silty gravels, <br />GM gravel -sand -silt <br />mixtures. <br />Atterberg limits Atterberg limits plotting <br />below "A" line, or in hatched area are <br />P.I. less than 4. borderline <br />Clayey gravels, <br />GC gravel -sand -clay <br />mixtures. <br />Atterberg limits classifications <br />above "A" line with requiring use of dual <br />P.I. greater than 7. symbols. <br />Cu = D60 / Dio greater than 6. <br />Cz = (D30)2 / (Dio x D60) between 1 & 3. <br />Sands <br />More than 50% of coarse fraction <br />passes No 4 sieve <br />Clean Sands <br />Well -graded sands <br />SW and gravelly <br />sands, little or no <br />fines. <br />Poorly -graded <br />SP sands and gravelly <br />sands, little or no <br />fines. <br />Not meeting both criteria for SW materials. <br />Sands with <br />Fines <br />SM Silty sands, sand- <br />silt mixtures. <br />Atterberg limits Atterberg limits plotting <br />below "A" line, or in hatched area are <br />P.I. less than 4. borderline <br />Clayey sands, <br />SC sand -clay <br />mixtures. <br />Atterberg limits classifications <br />above "A" line with requiring use of dual <br />P.I. greater than 7. symbols. <br />Fine Grained Soils <br />More than 50% passes No. 200 sieve * <br />Silts and Clays <br />Liquid Limit of 50% or less <br />Inorganic silts, <br />ML very fine sands, <br />rock flour, silty or <br />clayey fine sands. <br />Plasticity Index Chart <br />60 <br />Inorganic clays of <br />low to medium <br />CL plasticity, gravelly <br />clays, sandy clays, <br />silty clays, lean <br />clays. <br />50 <br />onanfo���a�f��a�o�off�e9��edm��� <br />°th ` <br />` <br />` <br />01 <br />CHS <br />Os <br />40 <br />A«e�tie�9L�m�«P�o«�9�na«neda�eaa�e <br />E <br />—symbols <br />Organic silts and <br />OL organic silty clays <br />of low plasticity. <br />J <br />r <br />z 30 <br />R <br />1CLS ils <br />une <br />a 20 <br />Silts and Clays <br />Liquid Limit greater than <br />50%. <br />Inorganic silts, <br />micaceous or <br />MH diatomaceous fine <br />sands or silts, <br />elastic silts. <br />10 <br />OH&MHSoils <br />CL-MLSoils <br />1 OL & M L Soils <br />Inorganic clays of <br />CH high plasticity, fat <br />clays. <br />0 <br />0 10 <br />20 <br />30 40 50 <br />Liquid <br />1 <br />60 <br />Limit <br />70 <br />80 <br />90 <br />100 <br />Organic clays of <br />OH medium to high <br />plasticity. <br />v <br />.t; R � <br />2 O <br />Peat, muck and <br />Pt other highly <br />organic soils. <br />Page 11 of 15 <br />