7818 LARIMER RD B Geotech Report 2022-10-25

AMERICAN GEOSERVICES DESCRIPTIVE TERMINOLOGY & SOIL CLASSIFICATION UNIFIED SOIL CLASSIFICATION SYSTEM UNIFIED SOIL CLASSIFICATION AND SYMBOL CHART COARSE -GRAINED SOILS (more than 50% of material is larger than No. 200 sieve size.) Clean Gravels (Less than 5% fines) _ GW Well -graded gravels, gravel -sand mixtures, little or no fines GRAVELS More than 50% °eo GP Poorly -graded gravels, gravel -sand of coarse o° mixtures, little or no fines fraction larger Gravels with fines (More than 12% fines) than No. 4-------- sieve size a GM Silty gravels, gravel -sand -silt mixtures GC Clayey gravels, gravel -sand -clay mixtures Clean Sands (Less than 5% fines) SW Well -graded sands, gravelly sands, little or no fines SANDS `" ------ ---- -------------- ----- 50% or more 3P Poorly graded sands, gravelly sands, of coarse little or no fines fraction smaller Sands with fines (More than 12% finest than No 4 sieve size k < : SM Silty sands, sand -silt mixtures SC Clayey sands, sand -clay mixtures FINE-GRAINED SOILS (50% or more of material is smaller than No. 200 sieve size.) Inorganic silts and very fine sands, rock ML flour, silty of clayey fine sands or clayey SILTS i silts with slight plasticity AND CLAYS Inorganic clays of low to medium Liquid limit " CL plasticity, gravelly clays, sandy clays, less than silty clays, lean clays 50% — --- — _ OL Organic silts and organic silty clays of - low plasticity Inorganic silts, micaceous or MH diatomaceous fine sandy or silty soils, SILTS elastic silts AND -- - -- --- CLAYS CH Inorganic clays of high plasticity, fat Liquid limit clays 50% or greater Organic clays of medium to high OH plasticity, organic silts HIGHLY - ORGANIC PT Peat and other highly organic soils SOILS LABORATORY CLASSIFICATION CRITERIA Cu = D60 greater than 4; Cc = D30 between 1 and 3 GW D 10 D10 x D60 GP Not meeting all gradation requirements for GW GM Atterberg limits below "A" line or P.I. less than 4 Above "A" line with P.I. between 4 and 7 are borderline cases GC Atterberg limits above "A" requiring use of dual symbols line with P.I. greater than 7 Cu = D60 greater than 4; Cc = _D30 between 1 and 3 SW D 10 D10 x D60 Sp Not meeting all gradation requirements for GW SM Atterberg limits below "A" Limits plotting in shaded zone line or P.I. less than 4 with P.I. between 4 and 7 are Atterberg limits above "A" borderline cases requiring use SC line with P.I. greater than 7 of dual symbols. Determine percentages of sand and gravel from grain -size curve. Depending on percentage of fines (fraction smaller than No. 200 sieve size), coarse -grained soils are classified as follows: Less than 5 percent .................................... GW, GP, SW, SP More than 12 percent .................................. GM, GC, SM, SC 5 to 12 percent ................... Borderline cases requiring dual symbols I PLASTICITY CHART I 60 50 a W 40 a ? 30 F tt 20 F= g 10 a 0 CH AE: LL -20) CL MH&OH L+ML ,,;; ML&OL 0 10 20 30 40 50 60 70 80 90 100 LIQUID LIMIT (LL) (%)