Agenda - Council Work Session - 02/28/2023

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UNIFIED SOIL CLASSIFICATION SYSTEM ASTM Designations: D 2487, D2488 Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Group Symbol Soil Classification Group Name' Coarse -Grained Gravels More Clean Gravels Cu>4 and 1<Cc<3E GW Well graded gravel' Soils More than 50% coarse Less than 5% than 50% fraction retained finest Cu<4 and/or 1>Cc>3E GP Poorly graded gravel' retained on on No. 4 sieve No. 200 sieve Gravels with Fines classify as ML or MH GM Silty gravel'.G.x Fines more than 12% fines c Fines classify as CL or CH GC Clayey gravel'.G.x Sands 50% or Clean Sands Cu>6 and 1<Cc<3E SW Well -graded sand' more of coarse Less than 5% fraction passes fineSD Cu<6 and/or 1>Cc>3E SP Poorly -graded sand' No. 4 sieve Sands with Fines classify as ML or MH SM Silty sandG.x.1 Fines more than 12% fines D Fines classify as CL or CH SC Clayey sandG.x.1 Fine -Grained Silts and Clays inorganic PI>7 and plots on or above CL Lean clayK.L.M Soils 50% or Liquid limit less "A" line) more passes than 50 PI<4 or plots below ML SiltK.L.M the No. 200 "A" line' sieve organiclimit—ovenOL g Liquid dried <0.75 Organic clayK.L.M.N (see Plasticity Liquid limit — not dried Organic siltK.L.M.o Chart below) Highly organic soil IUL 80 cD Z U5 Q .60 o_ Z W .40 20 0 Silts and Clays inorganic PI plots on or above "A" line Liquid limit 50 or more PI plots below "A" line SIEVE ANALYSIS Screen Opening (in.) i Sieve Number organic Liquid limit —oven dried <0.75 Liquid limit — not dried Primarily organic matter, dark in color, and organic in odor 3 2.1'/2 .1 3/4 % 4 10 20 40 60 .140 200 0 20 c u 2 D6o = 15mm 40 u 2 6o L Dso = 2.5mm u a 80 FF-t -D10 100 60 50 a p 40 Z i — i j U 30 J 20 = 0.075mm 10 7 4 CH Fat clayK.L.M MH Elastic siltK.L.M OH Organic clayK.L.M.P Organic siltK.L.M.Q PT PeatR For classification of fine-grained soils and fine-grained fraction of coarse -grained soils. Equation of "A" -line then PlHorizontal at 0.731 (LL-24 to0) L = 25.5. J4r;�' ` r �\�� Equation of "U"-line ` Vertical at LL = 16 to PI = 7. then PI = 0.9 (LL-8) Qv MH OR OH �- MLOROL AMERICAN ENGINEERING TESTING, INC. AMERICAN L-NUINLLPINU 1LSrINU Notes ABased on the material passing the 3-in (75-mm) sieve. 'If field sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name. Gravels with 5 to 12% fines require dual symbols: GW-GM well -graded gravel with silt GW-GC well -graded gravel with clay GP -GM poorly graded gravel with silt GP -GC poorly graded gravel with clay Sands with 5 to 12% fines require dual symbols: SW-SM well -graded sand with silt SW -SC well -graded sand with clay SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay (D30)2 ECU =D60/D10 Cc= D)o x D60 'If soil contains >15% sand, add "with sand" to group name. GIf fines classify as CL-ML, use dual symbol GC -GM, or SC-SM. "If fines are organic, add "with organic fines" to group name. 'If soil contains >15% gravel, add "with gravel" to group name. 'If Atterberg limits plot is hatched area, soil is a CL-ML silty clay. 'If soil contains 15 to 29% plus No. 200 add "with sand" or "with gravel", whichever is predominant. 'If soil contains >30% plus No. 200, predominantly sand, add "sandy" to group name. 'If soil contains >30% plus No. 200, predominantly gravel, add "gravelly" to group name. NPl>4 and plots on or above "A" line. OP1<<4 or plots below "A" line. PP1 plots on or above "A" line. QPl plots below "A" line. 'Fiber Content description shown below. 50 10 5 1.0 0:5 0A Ll 0 .10 .16 20 30 40 50 60 70 80 90 100 .110 PARTICLE SIZE IN MILLIMETERS LIQUID LIMIT (LL) 260 15 DL 2.52 C" — .Dio 0.075 — 200 D xo Dw 0.075 x 15 — 5'6 Plasticity Chart ADDITIONAL TERMINOLOGY NOTES USED BY AET FOR SOIL IDENTIFICATION AND DESCRIPTION Grain Size Gravel Percentages Consistency of Plastic Soils Relative Density of Non -Plastic Soils Term N-Value, BPF Term N-Value, BPF Term Particle Size Term Percent Boulders Over 12" A Little Gravel 3% - 14% Very Soft less than 2 Very Loose 0-4 Cobbles 3" to 12" With Gravel 15% - 29% Soft 2-4 Loose 5-10 Gravel #4 sieve to 3" Gravelly 30% - 50% Firm 5 - 8 Medium Dense 11 - 30 Sand #200 to #4 sieve Stiff 9-15 Dense 31 -50 Fines (silt & clay) Pass #200 sieve Very Stiff 16 - 30 Very Dense Greater than 50 Hard Greater than 30 Moisture/Frost Condition La.r�g Notes Peat Description Organic Description (if no lab tests) Soils are described as off, if soil is not peat (MC Column) D (Dry): Absence of moisture, dusty, dry to and is judged to have sufficient organic fines touch.content Laminations: Layers l os: yes less than Fiber Content to influence the Liquid Limit properties. M (Moist): Damp, although free water not /z" thick of Term (Visual Estimate) SliLhhd o-panic used for borderline cases. visible. Soil may still have a high differing material Root Inclusions water content (over "optimum"). or color. Fibric Peat: Greater than 67% With roots: Judged to have sufficient quantity W (Wet/ Free water visible, intended to Hemic Peat: 33 — 67% of roots to influence the soil Waterbearing): describe non -plastic soils. Lenses: Pockets or layers Sapric Peat: Less than 33% properties. Waterbearing usually relates to greater than '/2" Trace roots: Small roots present, but not judged sands and sand with silt. i f differing oerng thickto be in sufficient quantity to F (Frozen): Soil frozen material or color. significantly affect soil properties. 01 CLS021 (01/2022) AMERICAN ENGINEERING TESTING, INC.