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GENERAL NOTES
DRILLING & SAMPLING SYMBOLS:
SS : Split Spoon - 1 3/8" I.D., 2" O.D., unless otherwise noted
ST : Thin-Walled Tube - 2" O.D., unless otherwise noted
PA : Power Auger
HA : Hand Auger
DB : Diamond Bit - 4", N, B
AS : Auger Sample
HS : Hollow Stem Auger
PS : Piston Sample
WS : Wash Sample
FT : Fish Tail Bit
RB : Rock Bit
BS : Bulk Sample
PM : Pressuremeter
DC : Dutch Cone
WB : Wash Bore
Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2 inch OD split spoon, except where noted.
WATER LEVEL MEASUREMENT SYMBOLS:
WL : Water Level
WCI : Wet Cave In
DCI : Dry Dave In
AB : After Boring
WS : Wide Sampling
WD : While Drilling
BCR : Before Casing Removal
ACR : After Casing Removal
Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeable soils, the accurate determination of ground water levels is not possible with only short term observations.
DESCRIPTIVE SOIL CLASSIFICATION:
Soil classification is based on the Unified Soil Classification System and ASTM Designations D-2487 and D-2488. Course Grained Soils have more than 50% of their dry weight retained on a #200 sieve; they are describes as: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are described as: clays, if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse grained soils are defined on the basis of their relative in-place density and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff (CL); silty sand, trace gravel, medium dense (SM).
CONSISTENCY OF FINE-GRAINED SOILS:
| Unconfined Compressive Strength, Qu, psf | Consistency |
| < 500 | Very Soft |
| 500 - 1,000 | Soft |
| 1,001 - 2,000 | Medium |
| 2,001 - 4,000 | Stiff |
| 4,001 - 8,000 | Very Stiff |
| 8,001 - 16,000 | Hard |
| > 16,000 | Very Hard |
RELATIVE PROPORTIONS OF SAND AND GRAVEL
| Descriptive
Term(s) (of Components Also Present in Sample) |
% of Dry Weight |
| Trace | < 15 |
| With | 15 - 29 |
| Modifier | > 30 |
RELATIVE PROPORTIONS OF FINES
| Descriptive
Term(s) (of Components Also Present in Sample) |
% of Dry Weight |
| Trace | < 5 |
| With | 5 - 12 |
| Modifier | > 12 |
RELATIVE DENSITY OF COARSE-GRAINED SOILS:
| N - Blows/ft. | Relative Density |
| 0 - 3 | Very Loose |
| 4 - 9 | Loose |
| 10 - 29 | Medium Dense |
| 30 - 49 | Dense |
| 50 - 80 | Very Dense |
| 80+ | Extremely Dense |
GRAIN SIZE TERMINOLOGY
| Major Component Of Sample | Size Range |
| Boulders | Over 12 in. (300mm) |
| Cobbles | 12 in. to 3 in. (300mm to 75mm) |
| Gravel | 3 in. to #4 sieve (75mm to 4.75mm) |
| Sand | #4 to #200 sieve (4.75mm to 0.075mm) |
| Silt or Clay | Passing #200 sieve (0.075mm) |