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UNIFIED SOIL CLASSIFICATION SYSTEM lierracon
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<br /> Soil Classification
<br /> Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests Group Group Name B
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<br /> Symbol_,
<br /> Clean Gravels: Cu>_4 and 1 <_Cc<_3 E GW Well-graded gravel F
<br /> Gravels: Less than 5%fines c Cu<4 and/or[Cc<1 or Cc>3.0]E GP Poorly graded gravel F
<br /> More than 50%of
<br /> coarse fraction Fines classify as ML or MH GM Silty gravel F,G,H
<br /> retained on No.4 sieve Gravels with Fines:
<br /> Coarse-Grained Soils: More than 12%fines c Fines classify as CL or CH GC Clayey gravel F,G,H
<br /> More than 50%retained
<br /> on No.200 sieve Clean Sands: Cu>_6 and 1 <_Cc<_3 E SW Well-graded sand
<br /> Sands: Less than 5%fines o Cu<6 and/or[Cc<1 or Cc>3.0]E SP Poorly graded sand s
<br /> 50%or more of coarse
<br /> fraction passes No.4 Fines classify as ML or MH SM Silty sand G,H,I
<br /> Sands with Fines:
<br /> sieve More than 12%fines 13 Fines classify as CL or CH SC Clayey sand G,H,
<br /> PI>7 and plots on or above"A" CL Lean clay K,L,M
<br /> Inorganic:
<br /> Silts and Clays: PI<4 or plots below"A"line J ML Silt K,L,M
<br /> Liquid limit less than 50 Liquid limit-oven dried Organic clay K,�,M,H
<br /> Fine-Grained Soils: Organic: -- <0.75 OL
<br /> Liquid limit-not dried Organic silt K,L,M,o
<br /> 50%or more passes the
<br /> No.200 sieve PI plots on or above"A"line CH Fat clay K,L,M
<br /> 1 Inorganic:
<br /> Silts and Clays: PI plots below"A"line MH Elastic Silt K,I-,M
<br /> Liquid limit 50 or more
<br /> Organic: Liquid limit oven dried <0.75 OH Organic clay K,L,M,P
<br /> Liquid limit-not dried Organic silt K,L,M,Q
<br /> I Highly organic soils: Primarily(75-mm)organicsieve. matter,dark in color, and organic odor PT Peat
<br /> A Based on the material passing the 3-inch H If fines are organic,add"with organic fines"to group name.
<br /> B If field sample contained cobbles or boulders,or both,add"with cobbles I If soil contains>_15%gravel,add"with gravel"to group name.
<br /> or boulders, or both"to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML,silty clay.
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<br /> c Gravels with 5 to 12%fines require dual symbols: GW-GM well-graded K If soil contains 15 to 29%plus No.200,add"with sand"or"with
<br /> gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly gravel,"whichever is predominant.
<br /> graded gravel with silt,GP-GC poorly graded gravel with clay.
<br /> L D Sands with 5 to 12%fines require dual symbols: SW-SM well-graded
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<br /> If soil contains>_30%plus No.200 predominantly sand,add sand with silt,SW-SCwell-graded sand with clay,SP-SM poorly graded
<br /> sand with silt,SP-SC
<br /> -SC "sandy"to group name.poorly graded sand with clay. MY soil contains>_30%plus No.200, predominantly gravel,add
<br /> "gravelly"to group name.
<br /> (D30)2 N PI>_4 and plots on or above"A"line.
<br /> I E Cu=Dfio/D,° Cc= Q PI <4 or plots below"A"line.
<br /> Duo x Dso P PI plots on or above"A"line.
<br /> F If soil contains>_15%sand,add"with sand"to group name. Q PI plots below"A"line.
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<br /> G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
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<br /> For classification of fine-grained
<br /> soils and fine-grained fraction
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<br /> of coarse-grained soils •��e, �e
<br /> Equation of"A"-line �J,' +P
<br /> Y. Horizontal at P1=4 to LL=25.5.
<br /> X 40 — then PI=0.73(LL-20) 0+
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<br /> p Equation of"U"-line �, / of
<br /> Z Vertical at LL=16 to PI=7, G�
<br /> } 30 ' then PI=0.9(LL-8) 1
<br /> UF—
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<br /> 1.
<br /> H �Ol
<br /> 0) 20 _
<br /> a G MH or OH
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<br /> 7 -- CL- ML
<br /> 4 -- ML or OL
<br /> 0 10 16 20 30 40 50 60 70 80 90 100 11s
<br /> LIQUID?LIMIT(LL)
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