06-08-26 Planning Commission Meeting Packet

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Descriptive Terminology of Soil Standard D 2487 - 00 Classification of Soils for Engineering Purposes (Unified Soil Classification System) Rev. 7/07 DD Dry density, pcf WD Wet density, pcf MC Natural moisture content, % LL Liqiuid limit, % PL Plastic limit, % PI Plasticity index, % P200 % passing 200 sieve OC Organic content, % S Percent of saturation, % SG Specific gravity C Cohesion, psf Angle of internal friction qu Unconfined compressive strength, psf qp Pocket penetrometer strength, tsf Liquid Limit (LL) Laboratory TestsPlasticity Index (PI)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. Standard penetration test borings are designated by the prefix “ST” (Split Tube). All samples were taken with the standard 2” OD split-tube sampler, except where noted. Power auger borings were advanced by 4” or 6” diameter continuous- flight, solid-stem augers. Soil classifications and strata depths were in- ferred from disturbed samples augered to the surface and are, therefore, somewhat approximate. Power auger borings are designated by the prefix “B.” 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manually with a 1 1/2” or 3 1/4” diameter auger and were limited to the depth from which the auger could be manually withdrawn. Hand auger borings are indicated by the prefix “H.” 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 indicates thin-walled (undisturbed) tube sample. Note: All tests were run in general accordance with applicable ASTM standards. 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 above “A” line Relative Density of Cohesionless Soils Very loose ................................ 0 to 4 BPF Loose ....................................... 5 to 10 BPF Medium dense ......................... 11 to 30 BPF 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 a. Based on the material passing the 3-in (75mm) sieve. b. If field sample contained cobbles or boulders, or both, add “with cobbles or boulders or both” to group name. c. Cu = D60 / D10 Cc = (D30)2 D10 x D60 d. If soil contains 15% sand, add “with sand” to group name. e. 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 f. If fines classify as CL-ML, use dual symbol GC-GM or SC-SM. g. If fines are organic, add “with organic fines” to group name. h. If soil contains 15% gravel, add “with gravel” to group name. i. 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 j. If Atterberg limits plot in hatched area, soil is a CL-ML, silty clay. k. If soil contains 10 to 29% plus No. 200, add “with sand” or “with gravel” whichever is predominant. l. If soil contains 30% plus No. 200, predominantly sand, add “sandy” to group name. m. If soil contains 30% plus No. 200 predominantly gravel, add “gravelly” to group name. n. PI 4 and plots on or above “A” line. o. PI 4 or plots below “A” line. p. PI plots on or above “A” line. q. PI plots below “A” line. Poorly graded sand h Peat Well-graded gravel d PI plots on or above “A” line PI 7 and plots on or above “A” line j PI 4 or plots below “A” line j Fine-grained Soils50% or more passed theNo. 200 sieveCoarse-grained Soilsmore than 50% retained onNo. 200 sieveSoils Classification Gravels More than 50% of coarse fraction retained on No. 4 sieve Sands 50% or more of coarse fraction passes No. 4 sieve Silts and Clays Liquid limit less than 50 Highly Organic Soils Silts and clays Liquid limit 50 or more Primarily organic matter, dark in color and organic odor Group Symbol Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests a Group Name b GW GP GM GC SW SP SM CL ML OL OL SC Poorly graded gravel d Silty gravel d f g Clean Gravels 5% or less fines e Gravels with Fines More than 12% fines e Clean Sands 5% or less fines i Sands with Fines More than 12% i Fines classify as ML or MH Fines classify as CL or CH Clayey gravel d f g Well-graded sand h Fines classify as CL or CH Fines classify as ML or MH Silty sand f g h Clayey sand f g h Inorganic Organic Liquid limit - oven dried Liquid limit - not dried 0.75 Inorganic Organic PI plots below “A” line Lean clay k l m Liquid limit - oven dried Liquid limit - not dried 0.75 CH MH OH OH Fat clay k l m Elastic silt k l m Organic clay k l m n Organic silt k l m o Organic clay k l m p Organic silt k l m q Cu 6 and 1 Cc 3 C PT Cu 4 and 1 Cc 3 C Cu 4 and/or 1 Cc 3 C Cu 6 and/or 1 CC 3 C 0 10 16 20 30 40 50 60 70 80 90 100 110 7 “U” Line“A” Line 10 20 30 40 50 60 4 0 ML or OL MH or OHCL or OL CH or O H CL - ML Silt k l m