Agenda - Council - 09/10/2019 - Laserfiche WebLink

Home

BRAUN I NTE RTEC Descriptive Terminology of Soil Standard D 2487 Classification of Soils for Engineering Purposes ,„,. „„„„.„ (Unified Soil Classification System) Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests a Soils Classification Group Symbol Group Name h Coarse -grained Soils more than 50% retained on No 260 sieve Gravels More than 50% of coarse fraction retained on No. 4 sieve Clean Gravels Less than 5% fines e C. ? 4 and 11C, - 3 c GW Well -graded gravel" C < 4 andlor 1 > C > 3 c GP i Poorly graded gravel" Gravels with Fines More than 12% fines' Fines classify as ML or MH GM Silty gravel ary Fines classify as CL or CH GC Clayey gravel d r9 Sands 50% or more of coarse fraction passes No. 4 sieve Clean Sands Less than 5% fines I C, y 6 and 1 < C< < 3 c SW Well -graded sand h C < 6 and/or 1 > Cc> 3 c SP Poorly graded sand h Sands with Fines More than 12% Fines classify as ML or MH SM Silty sand °a" Fines classify as CL or CH SC Clayey sand rah Fine-grained Soils 50% or more passed the No. 200 sieve Silts and Claysk Liquid limit less than 50 Inorganic PI > 7 and plots on or above "A" liner CL Lean clay k I '" PI < 4 or plots below "A" liner ML 1 m Siltk Organic Liquid limit - oven dried < 0.75 OL OL Organic clay I m o Organic silt m o Liquid limit - not dried Silts and clays Li quid limn q 50 or more inorganic PI plots on or above "A" line CH Fat clay "' 'r PI plots below "A" line MH Elastic silt" I '" Organic Liquid limit- oven dried 0 75 OH OH g ykimp Organic cla Organic silt' 1 ' , < Liquid limit - not dried Highly Organic Soils Primarily organic matter, dark in color and organic odor PT Peat a. b. c. d. e. f. g. h. k. m. n. o. p q Plasticity Index (PI Based on the material passing the 3-inch (75mm) sieve. If field sample contained cobbles or boulders, or both, add "with cobbles or boulders or both" to group name. C, = 060/D1 o C . = (D30)2 Duo x 060 If soil contains >_15 % sand, add "with sand" 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 If 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. Sand 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 If Atterberg limits plot in hatched area, soil is a CL-ML, silty clay. If soil contains 10 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. PI >_ 4 and plots on or above "A" line. PI < 4 or plots below "A" line. PI plots on or above "A" lines. PI plots below "A" line. 60 50 40 30 20 10 7 4 0 DD WD MC LL PL PI P200 r - j # W f / O't` N> tvt r1 &d e e e_ �• e- e 0; €,4 Mil Cr OH ML or OL /f/7.— -1 ,.61 10 16 20 Dry density, pcf Wet density, pcg Natural moisture content, % Liquid limit, % Plastic limits, % Plasticity index, % % passing 200 sieve 30 40 50 60 70 Liquid Limit (LL) Laboratory Tests oc S SG C 0 qu qP 80 90 100 110 Organic content, % Percent of saturation, % Specific gravity Cohesion, psf Angle of internal friction Unconfined compressive strength, psf Pocket penetrometer strength, tsf Particle Size Identification Boulders over 12" Cobbles 3" to 12" Gravel Coarse 3/4" to 3" Fine No. 4 to 3/4" Sand Coarse No. 4 to No. 10 Medium No. 10 to No. 40 Fine No. 40 to No. 200 Silt <No. 200, PI< 4 or below "A" line Clay <No. 200, PI > 4 and on or about "A" line Relative Density of Cohesionless Soils Very Loose 0 to 4 BPF Loose 5 to 10 BPF Medium dense 11 to 30 PPF Dense 31 to 50 BPF Very dense over 50 BPF Consistency of Cohesive Soils Very soft 0 to 1 BPF Soft 2 to 3 BPF Rather soft 4 to 5 BPF Medium 6 to 8 BPF Rather stiff 9 to 12 BPF Stiff 13 to 16 BPF Very stiff 17 to 30 BPF Hard over 30 BPF Drilling Notes Standard penetration test borings were advanced by 3 1/4" or 6 1/4" ID hollow -stem augers, unless noted otherwise. Jetting water was used to clean out auger prior to sampling only where indicated on logs. All samples were taken with the standard 2" OD split -tube samples, except where noted. Power auger borings were advanced by 4" or 6" diameter continuous flight, solid -stern augers. Soil classifications and strata depths were inferred from disturbed samples augered to the surface, and are therefore, somewhat approximate. Hand auger borings were advanced manually with a 1 1/2" or 3 1/4" diameter auger and were limited to the depth from which the auger could be manually withdrawn. BPF: Numbers indicate blows per foot recorded in standard penetration test, also known as "N" value. The sampler was set 6" into undisturbed soil below the hollow -stem auger. Driving resistances were then counted for second and third 6" increments, and added to get BPF. Where they differed significantly, they are reported in the following form: 2/12 for the second and third 6" increments, respectively. WH: WH indicates the sampler penetrated soil under weight of hammer and rods alone; driving not required. WR: WR indicates the sampler penetrated soil under weight of rods alone; hammer weight, and driving not required. TW: TW indicates thin -walled (undisturbed) tube sample. Note: All tests were run in general accordance with applicable ASTM standards. Rev. 9/15