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14.330 SOIL MECHANICSSoil Compaction
SOIL COMPACTION BASICS
Courtesy of http://www.extension.umn.edu
Soil Compaction:Densification of soil by
the removal of air.
Figure courtesy of Soil Compaction: A Basic Handbook by MultiQuip.
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14.330 SOIL MECHANICSSoil Compaction
WHY COMPACT SOILS?
Figure courtesy of Soil Compaction: A Basic Handbook by MultiQuip.
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14.330 SOIL MECHANICSSoil Compaction
Volume (V)Weight (W) γ
Conceptual(Figure 4.1. Das FGE (2005))
MOIST UNIT WEIGHT () VS.MOISTURE CONTENT (w)
Silty Clay (LL=37, PI =14) Example(from Johnson and Sallberg 1960, taken
from TRB State of the Art Report 8, 1990)
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14.330 SOIL MECHANICSSoil Compaction
LABORATORY COMPACTION TESTS (i.e. PROCTORS)
Typical Proctor Test Equipment(Figure courtesy of test-llc.com)
6 inchMold
4 inch Mold
Ejector
Modified Hammer
Standard Hammer
Soil Plug
Soil Plug
Scale
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14.330 SOIL MECHANICSSoil Compaction
TestASTM/
AASHTO
HammerWeight
(lb)
Hammer Drop(in)
Compaction Effort
(kip-ft/ft3)Standard(SCDOT)
D698T-99
5.5 12 12.4
ModifiedD1557T-180
10 18 56
LABORATORY COMPACTIONTEST SUMMARY
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14.330 SOIL MECHANICSSoil Compaction
TestSTANDARD
ASTM D698/AASHTO T-99MODIFIED
ASTM D1557/AASHTO T-180
Method A B C A B C
Material≤ 20%
Retained by #4 Sieve
>20% Retained on
#4≤ 20%
Retained by 3/8 in Sieve
>20% Retained on
3/8 in< 30%
Retained by 3/4 in Sieve
≤ 20% Retained by
#4 Sieve
>20% Retained on
#4≤ 20%
Retained by 3/8 in Sieve
>20% Retained on
3/8 in< 30%
Retained by 3/4 in Sieve
Use Soil Passing Sieve #4 3/8 in ¾ in #4 3/8 in ¾ in
Mold Dia. (in) 4 4 6 4 4 6
No. of Layers 3 3 3 5 5 5
No. Blows/Layer 25 25 56 25 25 56
LABORATORY COMPACTION TEST SUMMARY
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14.330 SOIL MECHANICSSoil Compaction
Figure courtesy of Soil Compaction: A Basic Handbook by MultiQuip.
LABORATORY COMPACTIONTEST SUMMARY
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14.330 SOIL MECHANICSSoil Compaction
Automated ProctorEquipment
(Figure courtesy of Humboldt)
Manual Proctor Test(“What you WILL be doing”)
(Figure courtesy of westest.net)
LABORATORY COMPACTION TESTS (i.e. PROCTORS)
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14.330 SOIL MECHANICSSoil Compaction
wγ γd
1
From Soil Composition
notes:
Optimum Moisture Content OMC = 11.5%
Maximum DryDensity
MDD or d,max = 112.2 pcf
SP-SM% Fines = 6%
Zero Air Voids(ZAV) LineGs = 2.6
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14.330 SOIL MECHANICSSoil Compaction
s
w
s
wswszav
GwwG
γGe
G γ 111
Dry Unit Weight (d) (i.e. no water):
zav = Zero Air Void Unit Weight:
wγ
Volume (V))Solids (WWeight of γ s
d
1
ZERO AIR VOIDS LINE
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14.330 SOIL MECHANICSSoil Compaction
1. Soil TypeGrain Size DistributionShape of Soil GrainsSpecific Gravity of Soil Solids
2. Effect of Compaction EffortMore Energy – Greater Compaction
FACTORS AFFECTING SOILCOMPACTION
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14.330 SOIL MECHANICSSoil Compaction
Lee and Suedkamp (1972)
A. Single Peak(Most Soils)
B. 1 ½ PeakCohesive Soils LL<30
C. Double PeakCohesive Soils LL<30
orCohesive Soils LL>70
D. No Definitive PeakUncommonCohesive Soils LL>70after Figure 4.5. Das FGE (2005)
Moisture Content w
Dry
Uni
t Wei
ght
d
ABC
D
TYPES OFCOMPACTION CURVES
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14.330 SOIL MECHANICSSoil Compaction
Figure 4.6. Das FGE (2005).
In general:
Compaction Energy = d,max
Compaction Energy = OMC
EFFECT OFCOMPACTION ENERGY
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14.330 SOIL MECHANICSSoil Compaction
EFFECT OF COMPACTION ONCOHESIVE SOILS
Figure 4.22. Das FGE (2005).
OMC
Wet SideDry Side
Dry Side ParticleStructureFlocculent
Wet Side Particle
StructureDispersed
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14.330 SOIL MECHANICSSoil Compaction
Figure 4.23. Das FGE (2005).
Hydraulic Conductivity (k):Measure of how water flows through soils
In General:
Increasing w = Decreasing kUntil ~ OMC, then increasing whas no significant affect on k
EFFECT OFCOMPACTION ONCOHESIVE SOILS
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14.330 SOIL MECHANICSSoil Compaction
Figure 4.24. Das FGE (2005).
Unconfined Compression Strength (qu) :Measure of soil strength
In General:
Increasing w = Decreasing qu
Related to soil structure:Dry side – FlocculentWet Side – Dispersed
EFFECT OFCOMPACTION ONCOHESIVE SOILS
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14.330 SOIL MECHANICSSoil Compaction
FIELD COMPACTION EQUIPMENT4 Common Types:
1. Smooth Drum Roller2. Pneumatic Rubber Tired Roller3. Sheepsfoot Roller (Tamping Foot)4. Vibratory Roller (can be 1-3) Smooth Drum
Pneumatic Rubber Tired
Sheepsfoot Vibratory Drum
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14.330 SOIL MECHANICSSoil Compaction
Photographs courtesy of:
myconstructionphotos.smugmug.com
http://cee.engr.ucdavis.edu/faculty/boulanger/
Holtz and Kovacs (1981)
FIELD COMPACTION EQUIPMENT
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14.330 SOIL MECHANICSSoil Compaction
FineGrained
SoilsCourseGrained
Soils
CourseGrained
Soils
FIELD COMPACTION EQUIPMENT
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from Holtz and Kovacs (1981)
FIELD COMPACTION EQUIPMENT
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14.330 SOIL MECHANICSSoil Compaction
Relative Compaction (R or C.R.):
5 Common Field Test Methods:1. Sand Cone (ASTM D1556)2. Rubber Balloon Method (D2167)3. Nuclear Density (ASTM D2922)4. Time Domain Reflectometry (D6780)5. Shelby Tube (not commonly used)
100(%)max,
)( d
fieldd R
FIELD COMPACTION TESTING
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METHOD
SAND CONE(ASTM D1556)
BALLOON(ASTM D2167)
NUCLEAR(ASTM D2922 &ASTM D3017)
TDR(ASTM D6780)
Advantages • Large Sample• Accurate
• Large Sample• Direct Reading
Obtained• Open graded
material
• Fast• Easy to re-perform• More Tests
• Fast• Easy to re-perform• More Tests
Disadvantages• Time consuming• Large area
required
• Slow• Balloon breakage• Awkward
• No sample• Radiation• Moisture suspect
• Under research
Errors• Void under plate• Sand bulking• Sand compacted• Soil pumping
• Surface not level• Soil pumping• Void under plate
• Miscalibration• Rocks in path• Surface prep req.• Backscatter
• Under Research
after Soil Compaction: A Basic Handbook by MultiQuip.Photographs courtesy of Durham Geo/Slope Indicator and myconstructionphotos.smugmug.com.
FIELD COMPACTION TESTING
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14.330 SOIL MECHANICSSoil Compaction
Sand Cone Method(D1556-07)
F 13
Balloon Method(D2167-08)
Figures courtesy of Soil Compaction: A Basic Handbook by MultiQuip and TRB State of the Art Report 8, 1990.
Nuclear Method(D2922-05 & D3017-05)
FIELD COMPACTION TESTING
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14.330 SOIL MECHANICSSoil Compaction
Reference City of Lynchburg
SCDOTQC
SCDOTQA
USBR Earth
Manual
NAVFAC DM7.02 FM 5-410
Year 2004 1996 1996 1998 1986 1997
Roads 1 per liftper 300 LF
1 per liftper 500 LF
1 per liftper 2500 LF
1 per liftper 250 LF
Buildings or Structures
1 per liftper 5000 SF
Airfields 1 per liftper 250 LF
EmbankmentMass Earthwork
1 per liftper 500 LF
1 per liftper 2500 LF 2000 CY 500 CY
Canal/Reservoir Linings 1000 CY 500-1,000 CY
Trenches &Around Structures
1 per liftper 300 LF 200 CY 200-300 CY 1 per lift
per 50 LF
Parking Areas 1 per liftper 10000 SF
1 per liftper 250 SY
Misc.1 per areas of
doubtful compaction
1 per areas of doubtful
compaction
FIELD COMPACTION: TEST FREQUENCY
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14.330 SOIL MECHANICSSoil Compaction
State DOTs Maximum LiftHeight
Maryland, Massachusetts, Montana, North Dakota, Ohio, Oklahoma
Max. 0.15 m (6 in) lift before compaction
Connecticut, Kentucky Max. 0.15 m (6 in) lift after compaction
Alabama, Arizona, California, Delaware, Florida, Idaho, Illinois, Indiana, Iowa, Kansas, Maine, Minnesota, Mississippi, Missouri,
Oregon, South Carolina, South Dakota, Vermont, Virginia, Washington, Wisconsin
Max. 0.2 m (8 in) lift before compaction
Louisiana, New Hampshire, New Jersey, Texas, Wyoming
Max. 0.3 m (12 in) lift before compaction
New York Depends on Soil & Compaction Equipment
After Hoppe (1999), Lenke (2006), and Kim et al. (2009).
FIELD COMPACTION: LEFT HEIGHTS
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14.330 SOIL MECHANICSSoil Compaction
FIELD COMPACTION: ONE POINT PROCTORSC-T-29: Standard Method of Test for Field Determination of
Maximum Dry Density and Optimum Moisture Content of Soils by the One-Point Method
General Procedure:• Run one (1) Proctor Test DRY
of OMC.• Plot Test on Family of Curves• Match to a specific curve:
Take MDD and OMC Values from Table.
Family of Curves
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14.330 SOIL MECHANICSSoil Compaction
USCSSym.
CompactionEquipment
d,maxD698(lb/ft3)
Evaluation for Use as FillCompression & Expansion Embankment Subgrade Base Course
GWRubber TiredSmooth Drum
Vibratory Roller125 – 135 Almost
None Very Stable Excellent Good
GPRubber TiredSmooth Drum
Vibratory Roller115 – 125 Almost
NoneReasonably
StableExcellent to
Good Poor to Fair
GM Rubber TiredSheepsfoot
120 – 135 Slight Reasonably Stable
Excellent to Good Fair to Poor
GC Rubber TiredSheepsfoot
115 - 130 Slight Reasonably Stable Good Good to
Fair
COMPACTION CHARACTERISTICS & RATINGS: USCS SOILS
after U.S. Army Engineer Waterways Experiment Station (now ERDC). (1960). “The Unified Soil Classification System,” Technical Memorandum No. 3-357, Vicksburg, MS.
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14.330 SOIL MECHANICSSoil Compaction
USCSSym.
CompactionEquipment
d,maxD698(lb/ft3)
Evaluation for Use as FillCompression & Expansion Embankment Subgrade Base Course
SW Rubber TiredVibratory Roller
110-130 Almost None Very Stable Good Fair to Poor
SP Rubber TiredVibratory Roller
100-120 Almost None
Reasonable stable when
dense
Good to Fair Poor
SM Rubber TiredSheepsfoot
110-125 SlightReasonable stable when
dense
Good to Fair Poor
SC Rubber TiredSheepsfoot
105-125 Slight to Medium
Reasonable stable
Good to Fair Fair to Poor
COMPACTION CHARACTERISTICS & RATINGS: USCS SOILS
after U.S. Army Engineer Waterways Experiment Station (now ERDC). (1960). “The Unified Soil Classification System,” Technical Memorandum No. 3-357, Vicksburg, MS.
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COMPACTION CHARACTERISTICS & RATINGS: USCS SOILS
USCSSym.
CompactionEquipment
d,maxD698(lb/ft3)
Evaluation for Use as FillCompression & Expansion Embankment Subgrade Base Course
ML Rubber TiredSheepsfoot
95-120 Slight to Medium Poor Stability Fair to Poor Not
Suitable
CL SheepsfootRubber Tired
95-120 Medium Good Stability Fair to Poor Not Suitable
MH SheepsfootRubber Tired
70-95 HighPoor StabilityShould not be
usedPoor Not
Suitable
CH Sheepsfoot 80-105 Very high Fair Stability Poor to Very Poor
Not Suitable
after U.S. Army Engineer Waterways Experiment Station (now ERDC). (1960). “The Unified Soil Classification System,” Technical Memorandum No. 3-357, Vicksburg, MS.
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14.330 SOIL MECHANICSSoil Compaction
DYNAMIC COMPACTION
US44 ExpansionCarver, MA.Figure 1. FHWA-SA-95-037.
Figure courtesy of www.betterground.com
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14.330 SOIL MECHANICSSoil Compaction
after Figure 5 (FHWA-SA-95-037).
DYNAMIC COMPACTION
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DYNAMIC COMPACTION: US 44
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(from Hajduk et al., 2004)
DYNAMIC COMPACTION: US 44
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(from Hajduk et al., 2004)
DYNAMIC COMPACTION: US 44
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Figure 4.18. Das FGE (2005) (after Brown, 1977).Photograph courtesy of http://www.vibroflotation.com
VIBROFLOTATION
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Figure 4.19. Das FGE (2005) (after Brown, 1977).
VIBROFLOTATION
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Figure 4.20. Das FGE (2005).
VIBROFLOTATIONPROBE SPACING
VIBROFLOTATIONEFFECTIVE GRAIN
SIZEDISTRIBUTIONS
Figure 4.21. Das FGE (2005).
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14.330 SOIL MECHANICSSoil Compaction
Figure courtesy of www.groundimprovement.ch.
COMPACTION: ASSOCIATED COSTS