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EXHIBIT B <br />UNIFIED SOIL <br />CLASSIFICATION SYSTEM <br />UNIFIED SOIL CLASSIFICATION AND SYMBOL CHART <br />COARSE-GRAINED SOILS <br />(more than 50°k of material is larger than No. 200 sieve size.) <br /> Clean Gravels Less than 5% fines) <br /> '~~ <br />GW Well-graded gravels, gravel-sand <br /> <br />GRAVELS i• mixtures, little or no fines <br />More than 50°h ~~ Gp Poorly-graded gravels, gravel-sand <br />of coarse ~n mixtures, little or no fines <br />fraction larger Gravels with fines More than 12°~ fines <br />than No. 4 <br />sieve size GM Silty gravels, gravel-sand-silt miMures <br /> GC Clayey gravels, gravel-sand-Gay <br /> mixtures <br /> Clean Sands Less than 5% fines <br /> SW Well-graded sands, gravelly sands, <br /> <br />SANDS little or no fines <br /> <br />50% or more gp poodY graded sands, gravelly sands,. <br />of coarse liltie or no fines <br />fraction smaller Sands with fines More than 12% fines <br />than No. 4 <br />sieve size . . SM Silry sands, sand-sift mixtures <br /> `~ SC Clayey sands, sand-day mixtures <br /> ~~' <br />FINE-GRAINED SOILS <br />(50°k or more of material is smallerthan No. 200 sieve size.) <br /> Inorganic silts and very fine sands, rods <br /> ML flour, silty of dayey fine sands or dayey <br />SILTS <br />AND silts with slight plastidty <br />CLAYS ~ %~ <br />' Inorganic days of low to medium <br />Liquid limit ' CL Piastidty, gravelly days, sandy days, <br />less than ~;;" silty clays, lean days <br />50% <br /> - OL Organic silts and organic silty days of <br /> low plasticty <br /> Inorganic silts, micaceous or <br /> MH diatomaceous fine sandy or silty soils, <br />SILTS <br />N elastic silts <br />D <br />A - <br />CLAYS <br />CH Inorganic days of high plasticity, fat <br />Liquid limit days. <br />50% <br />or greater <br />~'; <br />OH Organic Gays of medium to high <br />' <br /> plasticity, organic si1Ls <br />HIGHLY - <br />ORGANIC PT Peat and other highly organic soils <br />SOILS <br /> LABORATORY CLASSIFICATION CRITERIA <br /> <br /> D30 <br />D60 <br /> greater than 4: Cc = <br />Cu = <br />between f and 3 <br />Gw D1o D1o xDso <br />GP Not meeting all gradation requirements for GW <br />GM Atterberg limits below `A` <br />line or P.I: less than 4 <br />Above `A` line with P.I. between <br />4 <br />d 7 <br />b <br />d <br />li <br /> an <br />are <br />or <br />er <br />ne cases <br />GC Atterberg limits above `A` <br />' requiring use of dual symbols <br /> line with P.1. <br />greater than 7 <br /> D30 <br />D60 <br /> Cu = <br />greater than 4; Cc = <br />between 1 and 3 <br />SW Dto Dto"Dso <br />Sp Not meeting all gradation requirements for GW <br />SM Atterberg limits below `A` Limits plotting in shaded zone <br /> line or P.I. less than 4 with P.I. between 4 and 7 are <br /> <br />SC Atterberg limits above "A" borderline cases requiring use <br /> line with P I greater than 7 of dual symbols. <br />Determine percentages of sand and gravel from grain-size curve. Depending <br />on percentage of fines (fraction smaller than No. 200 sieve size), <br />coarse rained sals are dass~ed as follows: <br />Less than 5 percent . ........................... GW, GP. SW. SP <br />More than 12 percent ............................ GM. GC, SM, SC <br />5 to 12 percent ............... Borderline cases requiring dual symbols <br />PLASTICITY CHART <br />60 <br />0 <br />a CH <br />w ~ .ALINE: <br />~ PI = 0.73 LL-20 <br />2 ~ <br />CL MHBAH <br />U 20 <br />r= <br />a~ <br />10 <br />g, ML.S.OL <br />00 10 20 30 40 50 60 70 80 90 100 <br />LIQUID LIMIT (LL) (%) <br />