1 10 100 1,000 10,000

Fine Grain

Coarse Grain

Claystone

Shale

Siltstone

Sandstone

Limestone

Schist

Gneiss

Quartzite

Granite

Basalt

Ultimate Bearing Pressure, qult

IGN

EO

US

B

ED

RO

CK

ME

TAM

OR

PH

IC

BE

DR

OC

KS

ED

IME

NTA

RY

BE

DR

OC

KS

OIL

Typical Penetration

Limit for Helical

Piles

0.1 1 10 100 1,000MPa

tsf

Index Soil Properties Index Rock Properties

Unit Weight Undrained Strength p-y Modulus Unit Weight

g f K n N g n Reduction(pcf) (deg) (psf) [kPa] (pci) (ksi) [MPa] (pcf) (ksI) [MPa] (ksi) [MPa] RQD Rock

Coa

rse

Gra

in Very Loose 1-4 70 [1.12] 25 - - 5 [0.1] 1 [9]

0.35

-

Sed

emen

tary Shale

50/B

OU

NC

E

140 [2.24] 6 [41] 3 [20] 0.35 % Quality %Loose 4-10 90 [1.44] 29 - - 25 [0.6] 2 [16] - Sandstone 145 [2.32] 20 [137] 6 [41] 0.32 0-25 very poor 0-7Medium 10-30 110 [1.76] 33 - - 90 [2.4] 3 [23] - Mudstone 169 [2.7] 5 [34] 25-50 poor 7-25Dense 30-50 120 [1.92] 39 - - 225 [6.2] 7 [47] - Dolomite 160 [2.56] 23 [157] 9 [62] 50-75 fair 25-56Very Dense >50 130 [2.08] 45 - - 500 [13.8] 20 [137] - Limestone 165 [2.64] 25 [172] 6 [41] 0.35 75-90 good 56-81

Fine

Gra

in

Very Soft 1-2 80 [1.28] - 200 [9] 30 [0.8] 1 [7] 0.5 0.06

Met

amor

phic Schist 165 [2.64] 15 [103] 12 [82] 0.2 90-100 excellent 81-100

Soft 2-4 85 [1.36] - 400 [19] 100 [2.7] 2 [14] 0.4 0.02 Quartzite 166 [2.65] 43 [294]Medium 4-8 90 [1.44] - 800 [38] 500 [13.8] 5 [31] 0.3 0.01 Gneiss 187 [2.99] 28 [196] Example:Stiff 8-15 100 [1.6] - 1,500 [71] 1,000 [27.6] 7 [47] 0.2 0.005 Marble 169 [2.7] 36 [245] Granite, RQD = 50Very Stiff >15 120 [1.92] - 3,000 [143] 2,000 [55.3] 10 [71] 0.1 0.004 Slate 169 [2.7] 28 [196] Reduction Factor = 0.5x0.5 = 0.25Soft < 30 120 [1.92] - 4,000 [191] 2,000 [55.3] 70 [482]

0.25

0.004

Igne

ous

Granite 166 [2.65] 40 [275] 12 [82] 0.28Medium 30-50 130 [2.08] - 10,000 [478] 3,000 [83] 280 [1931] 0.0035 Dolerite 190 [3.04] 50 [343] 16 [110] 0.25Hard 50-100 135 [2.16] - 20,000 [957] 4,000 [110.7] 520 [3586] 0.003 Gabbro 195 [3.12] 43 [294] 16 [110] 0.25Very Hard >100 140 [2.24] - 50,000 [2394] 5,000 [138.4] 700 [4828] 0.0025 Diorite 43 [294] 14 [96] 0.25

Basalt 178 [2.85] 60 [413] 15 [103] 0.3

SPT Blow Count

Angle of Friction Stress-Strain Modulus1

Poisson Ratio

Strain at 50% Peak Strength

SPT Blow Count

Unconfined Compressive

Strength1Modulus of Elasticity1

x103Poisson

Ratio

N55 su Es e50 qpeak Epeak

[g/cm3] [kg/cm3] [g/cm3] Factor2

Wea

ther

ed

Bed

rock

qpeak = 40 ksiqu = qpeak x 0.25 = 10 ksiEpeak = 12x103 ksiE = Epeak x 0.25 = 3x103 ksi

1Peak values given for specific rock types. Reduce for rock quality by multiplying values by Reduction Factor 2Reduction factor = RQD2

10 20 30 40 50 60 70 800

10

20

30

40

50

Liquid Limit, LL (%)

Plas

ticity

Inde

x, P

I (%

)

74

CL-ML ML

MH

CL

CH

"A" Line"U" Line

Plasticity (Clays) or Compressibility (Silts)LOW MEDIUM HIGH

Soil ClassificationParticle Diameter

in [mm]

CLAY Less Than 0.00008 [Less Than 0.002]

SILT 0.00008 to 0.003 [0.002 to 0.07]

SAND 0.003 to 0.25 [0.07 to 4.8]

GRAVEL 0.25 to 3 [4.8 to 76]

COBBLE 3 to 12 [76 to 300]

BOULDERS Greater Than 12 [Greater Than 300]

FINE GRAIN

COARSE GRAIN

Less Than #200

#200 to #4

Greater Than #4

Hand Measure

U.S. Standard Sieve Sizes

Shrinkage Limit Plastic Limit, PL Liquid Limit, LL

SOLID SEMISOLID PLASTIC LIQUID

Increasing Moisture Content

Plasticity Index, PI

Soil Classification Other Criteria

CO

AR

SE

GR

AIN G

RA

VE

L

GW<5%

GP not GW

GM12% - 50%

GC

SA

ND

SW<5%

SP not SW

SM12% - 50%

SC

FIN

E G

RA

IN

ML

>50%

CL

OL

MH

CH

OH

Note: Use dual symbols for all boderline soils (e.g. GP-GC, SP-SM, SC/CL, SM/ML, etc.)

Passing #200 Seive

<50% Passing

#4 Seive1

Cu>4 and 1<Cc<3 3

below "A" Line4

above "A" Line4

>50% Passing

#4 Seive1

Cu>4 and 1<Cc<3 3

below "A" Line4

above "A" Line4

LOW

P

LAS

TIC

ITY

Liquid Limit <50%

below "A" Line4

above "A" Line4

LL ratio <75% 2

HIG

H

PLA

STI

CIT

Y

Liquid Limit >50%

below "A" Line4

above "A" Line4

LL ratio <75% 2

1Percent passing based on weigth of coarse fraction only2Ratio of Liquid Limit after oven drying to Liquid Limit of natural soil3Coefficient of Uniformity, Cu = D60/D10 and Coefficient of Curvature, Cc = D30

2 / D10xD60 where D10, D30, and D60 are percent passing #10, #30, and #60 sieve, respectively4Refers to where Atterburg Limits plot relative to "A" Line5American Association of State Highway Transportation Officials (AASHTO), United States Department of Aggriculture (USDA), and 1968 New York City Building Code (NYCBC) use different criteria for classification. The classification given are examples of overlaps in these various systems and should not be considered absolute.

Description

Clean, well-graded gravel A-1 Stony Sand 6-65

Clean, poorly-graded gravel A-3 Stony Sand 6-65

Silty gravel A-2 Stony Sandy Loam 6-65

Clayey gravel A-2 Stony Sandy Clay 6-65

Clean, well-graded sand A-1 Sand 7-65

Clean, poorly-graded sand A-3 Sand 7-65

Silty sand A-2 Sandy Loam 8-65

Clayey sand A-2 Sandy Clay 9-65

Low Plasticity Silt A-4 Silt Loam 10-65

Low Plasticity Clay A-6 Clay, Clay Loam 9-65

Low Plasticity Organic Silt/Clay A-8 N/A 11-65

High Plasticity Silt A-5 Silt, Silt Loam 10-65

High Plasticity Clay A-7 Clay, Clay Loam 9-65

High Plasticity Organic Silt/Clay A-8 N/A 11-65

Similar AASHTO

Class5

Similar USDA Class5

Similar '68 NYCBC Class5

, D30, and D60 are percent passing #10, #30, and #60 sieve, respectively

American Association of State Highway Transportation Officials (AASHTO), United States Department of Aggriculture (USDA), and 1968 New York City Building Code (NYCBC) use different criteria for classification. The classification given are examples of overlaps in these various systems and should not be considered absolute.

Coarse Grain Soils Fine Grain Soils

Density N-Value Stiffness N-Value

Fluid <10% Fluid non-traversable

Very Loose 1-4 10%-15% Very Soft 1-2

Loose 4-10 15%-35% Soft 2-4

Medium 10-30 35%-65% Medium 4-8

Dense 30-50 65%-85% Stiff 8-15

Very Dense >50 >85% Very Stiff >15

WOR = Weight of Rod; WOH = Weight of Hammer; BNC = Bounce; NIL = Negligible

Relative Density

Field Identification

N55 N55

WOR - WOH

WOR - WOH

easily penetrated by fist

easily penetrated by thumb

moderate thumb penetration

difficult thumb penetrationindented by thumb nail

Fine Grain Soils Bedrock

Hardness N-Value

(tsf) [KPa]

NIL >>LL Fluid

<0.25 [<24] >LL Soft 1-30

0.25-0.5 [24-48] LL Medium 30-50

0.5-1.0 [48-96] PL-LL Hard 50-100

1.0-2.0 [96-192] PL Very Hard 100-BNC

>2.0 [>192] <PL Competent BNC

WOR = Weight of Rod; WOH = Weight of Hammer; BNC = Bounce; NIL = Negligible

Unconfined Compressive

StrengthMoisture Content

N55

WOR - WOH

Avg Grain Size

(in) [mm]

Clay 0.025 [0.001]

Silty Clay 0.127 [0.005]

Silt 0.25 [0.01]

Silty Sand 2.5 [0.1]

Sand 13 [0.5]

Typical Soil Type

(blow count/psi) [blow count/kPa]

0.069 [0.01]

0.046 [0.0066]

0.034 [0.005]

0.017 [0.0025]

0.011 [0.0016]

lCPT, Ratio N55/qc

Representative values for angle of internal friction (Modified from Bowles) NEED SOME COMMON ROCK STRENGTHS

Soil Notes:Gravel (GW/GP) 1. Use larger values as density increases

Coarse 40-55 2. Use larger values for more angular particlesSandy 35-50 3. Use larger values for well-graded materials

Sand (SW/SP)Loose 28-34Dense 43-50

Silt or Silty Sand (ML/SM)Loose 27-30Dense 30-35

Typical range of static stress-strain modulus, Es (Modified from Bowles)

Soil mClay (CL/CH) ksf [MPa] NC sensitive Clay

Very Soft 500-250 [2-15] 0.1-0.5 Es=200-500 suSoft 100-500 [5-25] 0.1-0.5 NC insensitive Clay to light OCMedium 300-1000 [15-50] 0.1-0.5 Es=750-1200 suHard 1000-2000 [50-100] 0.1-0.5 HOC ClaySandy 500-5000 [25-250] 0.2-0.3 Es=1500-2000 su

Glacial TillLoose 200-3200 [10-150]Dense 3000-1500 [150-720] Modified from BowlesVery Dense 10000-300 [500-1440] su=0.13N

Loess 300-1200 [15-60] 0.1-0.3 0.13ksf-ft/blowSand

Silty 140-450 [5-20]Loose 200-500 [10-25] Parry (1977)Dense 1000-1700 [50-81] note po is kPa

Sand and GravelLoose 1000-3000 [50-150] 0.3-0.4 qu=30NDense 2000-4000 [100-200] 0.3-0.4 Parry 1977

Shale 3000-3000 [150-5000] 0.1-0.4 qu is in kPaSilt 40-400 [5-20] 0.3-0.35

qu=9cIce 0.36Concrete 0.15

UNIT CONVERSIONCLAY tons kips lbs

1 2 2,000

kip-ft lb-ft

f (deg)

Es

f = 25 + 28 sqrt(N/po)

6 6,000

tsf psf psi0.25 500 3

in1.5

NEED SOME COMMON ROCK STRENGTHS Bearing/Unconfined

RQD Quality q'/q0-25 very poor 0-7%

2. Use larger values for more angular particles 25-50 poor 7-25%3. Use larger values for well-graded materials 50-75 fair 25-56%

75-90 good 56%-81%90-100 excellent 81%-100%

EXAMPLE (clay)N= 7 Clay 70 - 140qc= 490 Silt 140 - 210

kPa Silty Sand 210 - 360

Sand 360 - 570

EXAMPLE (clay)N= 7 Clay 14.3 - 7.1qc= 0.49 Silt 7.1 - 4.8

Mpa Silty Sand 4.8 - 2.8Sand 2.8 - 1.8

EXAMPLE (clay)N= 7 Clay 98.4 - 49.2qc= 0.071118 Silt 49.2 - 32.8

ksi Silty Sand 32.8 - 19.1Sand 19.1 - 12.1

NYCBCAllowable Bearing Capacity (tsf)Sands= 0.10N <6tsf Course

<4tsf Fine+increase 5% for every foot of burrial > 4'not to exceed 200%

kg N kN907 8,899 9

kg-ft N-ft N-m

Reduction Factor1,2

1qa'/qa = RQD2

2Bowles (1988)

Ratio qc/N70

qc = CPT Point Resistance (kPa)

Ratio N70/qc

qc = CPT Point Resistance (MPa)

Ratio N70/qc

qc = CPT Point Resistance (ksi)

2,722 26,698 8,138

kg/in2 N/in2 N/ft22 15 2224.869

ft m mm0.125 0.038 38

kN/m2 MPa23.948192 0.02394895.792767

Modulus

E'/E15%20% Bearing Pressure25% Igneous

30-70% RQD tsf Kpa70-100% 0-25 10 958

25-50 30 287350-75 65 622475-100 120 11491

Unconfined Unconfined Ultimate Bearing(tsf) (tsf) (tsf)

Soil Fine Grain 0.5Coarse Grain 0.5

Sedementary Claystone 22.5Shale 30.24 432 30Siltstone blur 44.1 630 44Sandstone 1440 38Limestone 72 1800 72

Metamorphic Schist 75.6 1080 76Gneiss blur 107.8 1540 108Quartzite blur 121.1 1730 121

Igneous Granite 201.6 2880 202Basalt 302.4 4320 302

Normal Wt Concrete 21675

qa = (1-2.5)qu allowable bearing capacity for pilesphi = 45 most competent rockNq = 197.9949Nc = 169.8528Ng = 198.9949

9000

c = qu/2reduction for quality

Reduction2

qu'=qu(RQD)2

Metamorphic Sedementary

0-50 10 958 10 95850-100 40 3830 25 2394

Ultimate Bearing Unit Wt E Poisson(pcf) (ksi) Ratio

13.560

112.5432 100-140 500-3000 0.25-0.45630

1440 145-150 500-6000 0.2-0.451800 165 500-15000 0.24-0.451080 165 1000-1200 0.18-0.22154017302880 168 2000-1200 0.26-0.34320 178 2500-1500 0.27-0.32

BowlesBowles

Bowles

LL A-Line A2-Line U-Line H-Line0 48 4

10 4 715.8 4 7 7.02

25.47945 4 7 15.7315129.58904 7 7 19.43014

50 21.9 37.8 050 21.9 37.8 10060 29.2 46.880 43.8 64.8

100 58.4 82.8

ta