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1 rerracon <br /> UNIFIED SOIL CLASSIFICATION SYSTEM GeoReport <br /> Soil Classification <br /> Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests a Group Group Name <br /> Symbol <br /> Clean Gravels: Cu 114 and 1<Cc<3 GW Well-graded gravel F <br /> Gravels: Less than 5%fines c Cu<4 and/or[Cc<1 or Cc>3.0] 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 116 and 1<Cc<3 E SW I 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 1 <br /> 50%or more of coarse <br /> fraction passes No.4 Sands with Fines: Fines classify as ML or MH SM Silty sand G,H, <br /> sieve <br /> More than 12%fines o Fines classify as CL or CH SC Clayey sand G,H, <br /> Inorganic: PI>7 and plots on or above"A" CL Lean clay K,L,M <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 clayK,L,M,N <br /> Fine-Grained Soils: Organic: <0.75 OL <br /> 50%or more passes the Liquid limit-not dried I Organic silt K,L,M,o <br /> PI plots on or above"A"line CH Fat clayKp L,M <br /> No.200 sieve Inorganic: <br /> Silts and Clays: PI plots below"A"line MH Elastic Silt K,L,M <br /> Liquid limit 50 or more Liquid limit-oven dried Organic clay K,L,M,P <br /> Organic: <0.75 OH Liquid limit-not dried Organic silt K,L,M,o <br /> Highly organic soils: Primarily organic matter,dark in color,and organic odor PT Peat <br /> A Based on the material passing the 3-inch(75-mm)sieve. 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. <br /> cGravels with 5 to 12%fines require dual symbols: GW-GM well-graded Kif 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 /> o Sands with 5 to 12%fines require dual symbols: SW-SM well-graded If soil contains El 30%plus No.200 predominantly sand,add <br /> "sandy"to group name. <br /> sand with silt,SW-SC well-graded sand with clay,SP-SM poorly graded <br /> sand with silt,SP-SC poorly graded sand with clay. MIf 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 /> E Cu=D6o/D,o Cc= O PI<4 or plots below"A"line. <br /> D10 X D60 P PI plots on or above"A"line. <br /> F If soil contains❑15%sand,add"with sand"to group name. OR plots below"A"line. <br /> G If fines classify as CL-ML,use dual symbol GC-GM,or SC-SM. <br /> 60 <br /> For classification of fine-grained <br /> soils and fine-grained fraction <br /> 50 of coarse-grained soils ��e ' e <br /> Equation of"N'-line <br /> Horizontal at PI=4 to LL=25.5. <br /> x 40 then PI=0.73(LL-20) <br /> p Equation of"U"-line C►�°� <br /> Z Vertical at LL=16 to PI=7, <br /> r 30 then PI=0.9(LL-8) <br /> r <br /> cj 20 <br /> g MH or OH <br /> IL ' <br /> 10 , <br /> 7 --- <br /> 4 - ML or OL <br /> 0 <br /> 0 10 16 20 30 40 50 60 70 80 90 100 110 <br /> LIQUID LIMIT (LL) <br />