levee overtopping and intelligent compaction lecture-24sep2009.pdf · 11. soil cation exchange cap...

Jean-Louis BRIAUD – Texas A&M University

1

LEVEE OVERTOPPINGAND

INTELLIGENT COMPACTION

The 2009 Charles W. Hair Memorial Lecture

byJean-Louis BRIAUD, PhD, PEProfessor andHolder of the Buchanan ChairTexas A&M University

LEVEE OVERTOPPING

J-L Briaud, Texas A&M University

1 MPa = 150 psi10 kN = 1 ton

25 mm = 1 inch



5

Input to an erosion problem

•Soil (Erodibility)

•Water (Velocity)

•Geometry (Dimensions)


6


7

Relationship between the erosion rate and the velocity of the water near the soil-water interface.

Relationship between the erosion rate and the shear stress at the soil-water interface.

( )Z f τ=

DEFINITION OF SOIL ERODIBILITY

Constitutive Law fo Soil Erosion


8

EFA - EROSION FUNCTION APPARATUS


9


10

Scour Rate vs Shear Stress

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

0.1 1.0 10.0 100.0

Shear Stress (N/m2)

Scou

r R

ate

(mm

/hr)

Sand D50=0.3 mm

Scour Rate vs Velocity

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

0.1 1.0 10.0 100.0

Velocity (m/s)

Scou

r R

ate

(mm

/hr)

Sand D50=0.3 mm

EROSION FUNCTION FOR A FINE SAND


11

Scour Rate vs Shear Stress

0.01

0.10

1.00

10.00

100.00

0.1 1.0 10.0 100.0

Shear Stress (N/m2)

Scou

r R

ate

(mm

/hr)

Porcelain Clay PI=16%Su=23.3 Kpa

Scour Rate vs Velocity

0.01

0.10

1.00

10.00

100.00

0.1 1.0 10.0 100.0

Velocity (m/s)

Scou

r R

ate

(mm

/hr)

Porcelain Clay PI=16%Su=23.3 Kpa

EROSION FUNCTION FOR A LOW PI CLAY


12NIAGARA FALLS11000 m of lateral erosion from Lake Ontario

towards Lake Erie in 12000 years or 0.1 mm/hr

From Google Earthhttp://www.iaw.com/~falls/origins.html

http://www.samizdat.qc.ca/cosmos/origines/niagara/niagara.htm

Lake Erie

Lake Ontario

Niagara River1841

1841

2006

Niagara Falls


13GRAND CANYON

1600 m of vertical erosion by the Colorado Riverin 10 Million years or 0.00002 mm/hr


14

ERODIBILITY CATEGORIES (Velocity)

0.1

1

10

100

1000

10000

100000

0.1 1.0 10.0 100.0Velocity (m/s)

Very HighErodibility

I

HighErodibility

II

MediumErodibility

IIILow

Erodibility IV

Very LowErodibility

V

Erosion Rate

(mm/hr)

-Fine Sand-Non-plastic Silt

-Medium Sand-Low Plasticity Silt -Fine Gravel

-Coarse Sand -High Plasticity Silt-Low Plasticity Clay

-All fissured Clays

-Cobbles-Coarse Gravel

-High Plasticity Clay

-Riprap

- Increase in Compaction (well graded soils)- Increase in Density

- Increase in Water Salinity (clay)

Non-ErosiveVI-Intact Rock

-Jointed Rock (Spacing < 30 mm)

-Jointed Rock (30-150 mm Spacing)

-Jointed Rock (150-1500 mm Spacing)

-Jointed Rock (Spacing > 1500 mm)


15

CRITICAL VELOCITY vs GRAIN SIZE

0.01

0.1

1

10

100

1000

1E-06 1E-05 0.0001 0.001 0.01 0.1 1 10 100 1000 10000

Mean Grain Size, D50 (mm)

Critical Velocity,

Vc

(m/s)

CLAY SILT SAND GRAVEL RIP-RAP & JOINTED ROCK

Vc = 0.35 (D50)0.45Vc = 0.1 (D50)-0.2

Vc = 0.03 (D50)-1

US Army Corps of Engineers EM 1601

INTACT ROCK

Joint Spacing for Jointed Rock


POCKET ERODOMETERPET test result = Depth of hole in mm after 20 squirts at 8 m/s

16

$0.49 atWalMart


POCKET ERODOMETERPET test result = Depth of hole in mm after

20 squirts at 8 m/s

17


POCKET ERODOMETERPET test result = Depth of hole in mm after

20 squirts at 8 m/s

18


Velocity Calibration

19

0 2xxvHg

=


20

mm mmmm

mm

mm


21

9. Soil clay minerals10. Soil dispersion ratio11. Soil cation exchange cap12. Soil sodium absorption rat13. Soil pH14. Soil temperature15. Water temperature16. Water salinity17. Water pH

Erodibility depends on soil properties

1. Soil water content2. Soil unit weight 3. Soil plasticity index4. Soil undrained shear str.5. Soil void ratio6. Soil swell7. Soil mean grain size8. Soil percent passding #200


22

NO SIMPLE CORRELATION !

CSS vs. Su

R2 = 0.1093

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00

Su(kPa)

CSS

(Pa)


23

EFA test onCreamy Peanut Butter

Su = 1.8 kPaVc = 1.4 m/s

0.1

1

10

100

1000

10000

100000

0.1 1.0 10.0 100.0

Velocity (m/s)


I

HighErodibility

II

MediumErodibility

III

LowErodibility

IV

Very LowErodibility

V

Erosion Rate

(mm/hr)

0.1

1

10

100

1000

10000

100000

0 1 10 100 1000 10000 100000

Shear Stress (Pa)


I

HighErodibility

IIMedium

Erodibility III

LowErodibility

IV

Very LowErodibility

V

Erosion Rate

(mm/hr)


24



•Water (Velocity)



25

Shear Stress Applied by Water

dz


26


27


28

Flow Hydrograph


29

Obtaining a design flood valueFlood-frequency curve based on Original Hydrograph

(1931-1999)

y = -2491.6Ln(x) + 12629R2 = 0.9563

0

5000

10000

15000

20000

0.1110100

Percent probability of exceedance in X years

Stre

amflo

w (m

3 /sec)

100year flood: 12629m3/s500year flood: 16639m3/s


30

Probably of Exceedance - PoE

100 yr 53% PoE, v100 = 2.8* m/s 500 yr 13.9% PoE, v500 = 3.25* m/s 10000 yr 0.75% PoE, v10000 = 3.95* m/s

* Example for Woodrow Wilson Bridge for 75 year design life.

Structural Eng. operate at a Prob. of Exceedance of 0.1%?Geotechnical Eng. operate at a Prob. of Exceedance of 1%?Hydraulic Eng. operate at a Prob. of Exceedance of 10%?


31



•Water (Velocity)



32

PIER SIZE & SHAPE for PIER SCOUR


33

RADIUS OF CURVATURE FOR MEANDERS


34

OVERTOPPING OF LEVEES


35

RANS Equations Continuity equation

Momentum (RANS) Equations

Energy Equation

0)U(t m,

m =+∂∂ ρρ

( ) ( )m,

in,

mnm,

imimmnmimn

nmlmn

ilimm,

im,

mi

Ugpgg

Ueg2RUUt

U

µξΩΩξΩΩρ

Ωρρ

+−=−+

+

++

∂∂

( ) ( )

( ) uuUUgguuUU DtDpKTgTuTU

tTC

jn

im

jn

im

mnij

nm

mn

nm

mn

mnmn

mm

mm

p

,,,,,,,,

,,,,

+++−=Φ

Φ++=

′++∂∂

µ

ρ


36


37


38On 29 August 2005, Hurricane Katrina hit the Coast of the Gulf of Mexico


39

Hurricane = 250 miles in diameter

Travel speed = 25 mph

Time on a levee or a bridge = 10 hours

Number of wave cycles = 6000


40

Created by friction between the windand the water, a storm surge develops


41STORM SURGE

8.5 m

4.6 m

3.0 m


42


43


44


45


46


47

TO SCALE

NOT TO SCALE


48


49


50

Flood Return Periodused in design in the Netherlands (levees)

1/10,000 for most populated areas 1/4,000 for less populated areas

Flood Return Periodused in design in the USA (bridges)

1/500 with Factor of Safety of 1 1/100 with normal Factor of Safety

Overtopping of levees not considered in levee design in the USA


51


52

EFA - EROSION FUNCTION APPARATUS


53EFA TEST RESULTS - Erosion rate vs velocity

0.1

1

10

100

1000

10000

100000

0.1 1.0 10.0 100.0Velocity (m/s)S1-B1-(0-2ft)-TW S1-B1-(2-4ft)-SW S2-B1-(0-2ft)-TWS2-B1-(2-4ft)-SW S3-B1-(2-4ft)-SW S3-B2-(0-2ft)-SWS3-B3-(0-1ft)-SW S4-(0-0.5ft)-LC-SW S4-(0-0.5ft)-HC-SWS5-(0-0.5ft)-LT-SW S6-(0-0.5ft)-LC-SW S7-B1-(0-2ft)-TWS7-B1-(2-4ft)-SW S8-B1-(0-2ft)-TW S8-B1-(2-4ft)-L1-SWS8-B1-(2-4ft)-L2-SW S11-(0-0.5ft)-LC-TW S11-(0-0.5ft)-HC-TWS12-B1-(0-2ft)-TW S12-B1-(2-4ft)-SW S15-Canal Side-(0-0.5ft)-LC-SWS15-CanalSide-(0-0.5ft)-HC-SW S15-Levee Crown-(0-0.5ft)-LT-SW S15-Levee Crown-(0.5-1.0ft)-LT-SW


I

HighErodibility

II MediumErodibility

IIILow

Erodibility IV

Very LowErodibility

V

Erosion Rate

(mm/hr)


54

NUMERICAL SIMULATION


55

t = 0.80 sec

t = 1.28 sec

t = 1.60 sec

t = 1.92 sec

t = 2.39 sec


56SHEAR STRESSES ON LEVEE SURFACE


57EFA TEST RESULTS - Erosion rate vs shear stress

0.1

1

10

100

1000

10000

100000

0 1 10 100 1000 10000 100000Shear Stress (Pa)

S1-B1-(0-2ft)-TW S1-B1-(2-4ft)-SW S2-B1-(0-2ft)-TWS2-B1-(2-4ft)-SW S3-B1-(2-4ft)-SW S3-B2-(0-2ft)-SWS3-B3-(0-1ft)-SW S4-(0-0.5ft)-LC-SW S4-(0-0.5ft)-HC-SWS5-(0-0.5ft)-LT-SW S6-(0-0.5ft)-LC-SW S7-B1-(0-2ft)-TWS7-B1-(2-4ft)-SW S8-B1-(0-2ft)-TW S8-B1-(2-4ft)-L1-SWS8-B1-(2-4ft)-L2-SW S11-(0-0.5ft)-LC-TW S11-(0-0.5ft)-HC-TWS12-B1-(0-2ft)-TW S12-B1-(2-4ft)-SW S15-Canal Side-(0-0.5ft)-LC-SWS15-CanalSide-(0-0.5ft)-HC-SW S15-Levee Crown-(0-0.5ft)-LT-SW S15-Levee Crown-(0.5-1.0ft)-LT-SW


IHigh

Erodibility II

MediumErodibility

IIILow

Erodibility IV

Very LowErodibility

V

Erosion Rate

(mm/hr)


58

LEVEES – FAILED and NOT FAILED

0.1

1

10

100

1000

10000

100000

0.1 1.0 10.0 100.0Velocity (m/s)S2-B1-(0-2ft)-TW S2-B1-(2-4ft)-SW S3-B1-(2-4ft)-SW

S3-B2-(0-2ft)-SW S3-B3-(0-1ft)-SW S4-(0-0.5ft)-LC-SW

S5-(0-0.5ft)-LT-SW S6-(0-0.5ft)-LC-SW S15-Canal Side-(0-0.5ft)-LC-SW

S15-CanalSide-(0-0.5ft)-HC-SW S15-Levee Crown-(0-0.5ft)-LT-SW S15-Levee Crown-(0.5-1.0ft)-LT-SW


I

HighErodibility

II MediumErodibility

IIILow

Erodibility IV

Very LowErodibility

V

Erosion Rate

(mm/hr)

Note:- Solid circles = levee breaches- Empty circles = no levee damage


59

LEVEE OVERTOPPING CHART

0.1

1

10

100

1000

10000

100000

0.1 1.0 10.0 100.0

Velocity (m/s)

ErosionRate

(mm/hr)


I

HighErodibility

IIMedium

Erodibility III

LowErodibility

IV

Very LowErodibility

V

TRANSITIONZONE

PRONE TOFAILURE BY

OVERTOPPING

PRONE TO RESIST

OVERTOPPING


60


- Strong roots- Dense growth- High, flexible, overlapping bladed leaves- The idea is to form a mat of grass so that

the water never touches the soil

61

INTELLIGENT COMPACTION

and

MODULUS BASED CONTROL


CURRENT PRACTICEBased on Density

• LAB: Proctor test to get dry density vs. water content curve

• SPEC: x% of γd max within range of w opt

• FIELD: Compact and check that γd and w meet the specs


• LAB : Proctor Test



Water Content (%)

3 9 15 2114

16

18

20

Dry

Den

sity

(kN

/m3 )

γd max

w opt

S = 1S = 0.9

Water Content (%)

3 9 15 2114

16

18

20

Dry

Den

sity

(kN

/m3 )

γd max

w opt

S = 1S = 0.9

• SPECIFICATIONS. X % of γd max within range of w opt

• FIELD


Nuclear Density MeterFor γd and w


Dry Density: Advantages and Disadvantages

1. AdvantagesAccumulated knowledgeWell defined parameterIndication of solids per unit volume

2. DisadvantagesNot related to designNot very sensitiveNot easy to measure quickly in field


FUTURE PRACTICEBased on Modulus

• LAB: Modulus test to get modulus vs. water content curve

• SPEC: x% of E max

within range of w opt

• FIELD: Intelligent compaction and check that E max and w meet the specs



• LAB : Modulus Test


Water Content (%)6 10 14 18

Mod

ulus

(MPa

)

0

20

40

Sand

Clay

E max

w opt

• SPECIFICATIONS X % of E max within range of w opt

• FIELD


Modulus MeterFor E and w

Intelligent Compaction

EIC


Modulus: Advantages and Disadvantages

1. AdvantagesDirectly related to designVery sensitive to water contentEasy to measure quickly in field

2. DisadvantagesMany influencing factorsNo lab test to get E vs. wNo target valuesNew concept


WHICH MODULUS?


Which Modulus? PLATE MODULUS in FIELD


BPT: Briaud Plate Test

Example of same modulus testin lab and in field


BCD Test: Briaud Compaction Device

BCD on Proctor Mold BCD in the Field

Silty Sand (Mold #7)

0

10

20

30

40

50

0 2 4 6 8 10 12 14Water Content (%)

Mod

ulus

(Mpa

)

0

4

8

12

16

20

Dry

Uni

t Wei

ght (

kN/m

3 )

Plate Reload Modulus (MPa)

Dry Unit Weight (kN/m^3)



0

10

20

30

40

0 2 4 6 8 10 12 14Water Content (%)

Mod

ulus

(MPa

)

0

4

8

12

16

20

Dry

Unit

Wei

ght (

kN/m

3 )





0

10

20

30

40

0 2 4 6 8 10 12Water Content (%)

Mod

ulus

(MPa

)

0

4

8

12

16

20

Dry

Uni

t Wei

ght (

kN/m

3 )




Sand + Porcelain Clay (Mold #5)

0

10

20

30

40

0 2 4 6 8 10 12 14 16Water Content (%)

Mod

ulus

(M

Pa)

0

4

8

12

16

20

Dry

Uni

t W

eigh

t (k

N/m

3 )


Dry Unit Weight (kN/m^3))


Sand + Porcelain Clay (Mold #6)

0

10

20

30

40

0 2 4 6 8 10 12 14 16Water Content (%)

Mod

ulus

(M

Pa)

0

4

8

12

16

20

Dry

Uni

t W

eigh

t (k

N/m

3 )

Plate Reload Modulus (MPa)Dry Unit Weight (kN/m^3)


Sand + Porcelain Clay


0

20

40

60

0 2 4 6 8 10 12 14 16Water Content (%)

Mod

ulus

(M

pa)

0

4

8

12

16

20

Dry

Uni

t W

eigh

t (k

N/m

3 )



• Only one of those three is not enough

• Two of those three are sufficient

• All three would be nice


1. Density?2. Modulus?3. Water Content?

Conventional Compaction (static or vibratory smooth drum

or sheep-foot)


Intelligent Vibratory Compaction

• Instrumented vibrating rollers• Measure roller accel. as a function of time• Calculate a soil modulus• That modulus is independent of the roller• Intelligent roller modifies automaticallyinstantaneously settings (force, ampl., freq.)to meet the target modulus


Recompaction of soft formation area with VARIOCONTROL automatic mode, presetting ( target value ) EVIB = 80 MN/m²

From Acceleration to Stiffness2 cos( ) ( )B d B d d d u u f dk x d x m x m r t m m g+ + = Ω Ω + +

FB: soil-drum-interaction-force md: mass of the drum (kg)xd: vert. disp. of drum (m) : acceleration of drummf: mass of the frame (kg) mu: unbalanced mass (kg)ru: radial distance for mu Ω = g: acc. due to gravity (m/sec2) f: frequency of rotating shaft (Hz)

: velocity of drum kB: stiffness of soildB: damping coefficient (dB ~ 0.2)

dx

dx

2 fπ

dx


From Stiffness to Modulus(experimental)


From AMMANN

Soil Modulusfor Intelligent Compaction

Soil: 5 MPa unacceptable200 MPa excellent


Soil layers Density Bearing capacity Eveness(Standard Proctor) (load bearing test, EV2) (4 m straight edge)

Laying and compaction specification for road construction in Germany

Subbase 100 - 103 % * 100 - 150 MN/m² * 20 mm

Capping layer 100 - 103 % * 100 - 120 MN/m² * 40 mm

Formation 97 - 100 % * 45 - 80 MN/m² * 60 mm

* depending on road classification and road design

Specifications based on Modulus


From BOMAG


Triangular Rollers

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600

Dep

th(m

)

σ(kpa)

Influence Depth

σ(Kpa)


THANK YOU

[email protected]


levee overtopping and intelligent compaction lecture-24sep2009.pdf · 11. soil cation exchange cap...

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