2 acknowledgements - ceprofs lecture-12feb2007.pdf · 40.00 45.00 0.00 20.00 40.00 60 ... uu u u...
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Jean-Louis BRIAUD – Texas A&M University
1
CASE HISTORIES IN SOIL AND ROCK EROSION
Woodrow Wilson Bridge, Brazos River Meander, Normandy Cliffs, and New Orleans Levees
The 9th Ralph B. Peck Lecture
byJean-Louis BRIAUD, PhD, PEProfessor andHolder of the Buchanan ChairTexas A&M University
Jean-Louis BRIAUD – Texas A&M University
2
HamnHamn--ChingChing Chen (Texas A&M), Chen (Texas A&M), KuangKuang--An Chang An Chang (Texas A&M), (Texas A&M), AnandAnand GovindasamyGovindasamy (Texas A&M), (Texas A&M), NamgyuNamgyu Park (Texas A&M), Po Park (Texas A&M), Po YehYeh (Texas A&M), (Texas A&M), Jennifer Nicks (Texas A&M), OkJennifer Nicks (Texas A&M), Ok--YounYoun Yu (Texas Yu (Texas A&M), A&M), RemonRemon AbdelmalakAbdelmalak (Texas A&M), (Texas A&M), XingnianXingnianChen (Texas A&M), Rick Chen (Texas A&M), Rick EllmanEllman ((MueserMueser Rutledge), Rutledge), Bea Hunt (Hardesty & Hanover), Stan Davis Bea Hunt (Hardesty & Hanover), Stan Davis (Maryland SHA), Sterling Jones (FHWA), Rune (Maryland SHA), Sterling Jones (FHWA), Rune StoresundStoresund (UC Berkeley), Ray Seed (UC Berkeley), (UC Berkeley), Ray Seed (UC Berkeley), Bob Bea (UC Berkeley), Tom Dahl (Bob Bea (UC Berkeley), Tom Dahl (TxDOTTxDOT), Bob ), Bob Warden (Texas A&M), Mark Everett (Texas A&M), Warden (Texas A&M), Mark Everett (Texas A&M), (ABMC), Phil Buchanan (Buchanan Soil Mechanics) (ABMC), Phil Buchanan (Buchanan Soil Mechanics)
ACKNOWLEDGEMENTSACKNOWLEDGEMENTS
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Jean-Louis BRIAUD – Texas A&M University
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••1972 1972 -- TerzaghiTerzaghi and Peckand Peck
••1975 1975 -- PhD letterPhD letter
••1993 1993 -- Buchanan LectureBuchanan Lecture
••1998 1998 -- AdministrationAdministration
••2006 2006 -- Peck LecturePeck Lecture
Professor PECKProfessor PECKFor his influence on my careerFor his influence on my career
Jean-Louis BRIAUD – Texas A&M University
4
1.1.Fundamentals of Soil ErosionFundamentals of Soil Erosion
2.2.Woodrow Wilson BridgeWoodrow Wilson Bridge
3.3.Brazos River MeanderBrazos River Meander
4.4.Normandy CliffsNormandy Cliffs
5.5.New Orleans LeveesNew Orleans Levees
3
Jean-Louis BRIAUD – Texas A&M University
5
Input to an erosion problemInput to an erosion problem
••Soil (Erodibility)Soil (Erodibility)
••Water (Velocity)Water (Velocity)
••Geometry (Dimensions)Geometry (Dimensions)
Jean-Louis BRIAUD – Texas A&M University
6No Flow Condition
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Jean-Louis BRIAUD – Texas A&M University
7Flow Condition
Jean-Louis BRIAUD – Texas A&M University
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9
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 for Soil Erosion
Jean-Louis BRIAUD – Texas A&M University
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EFA EFA -- EROSION FUNCTION APPARATUSEROSION FUNCTION APPARATUS
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Jean-Louis BRIAUD – Texas A&M University
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12
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
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Jean-Louis BRIAUD – Texas A&M University
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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
Jean-Louis BRIAUD – Texas A&M University
14NIAGARA 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
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Jean-Louis BRIAUD – Texas A&M University
15GRAND CANYON
1600 m of vertical erosion by the Colorado Riverin 10 Million years or 0.00002 mm/hr
Jean-Louis BRIAUD – Texas A&M University
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If your faucet If your faucet drips on a drips on a pebble for 20 pebble for 20 million years,million years, will there be will there be
a hole in the a hole in the pebble?pebble?
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Jean-Louis BRIAUD – Texas A&M University
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ERODIBILITY CATEGORIES (velocity)ERODIBILITY CATEGORIES (velocity)
0.1
1
10
100
1000
10000
100000
0.1 1.0 10.0 100.0
Velocity (m/s)
ErosionRate
(mm/hr)
Very HighErodibility
I
HighErodibility
IIMedium
Erodibility III
LowErodibility
IV
Very LowErodibility
V
Jean-Louis BRIAUD – Texas A&M University
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ERODIBILITY CATEGORIES (shear)ERODIBILITY CATEGORIES (shear)
0.1
1
10
100
1000
10000
100000
0 1 10 100 1000 10000 100000Shear Stress (Pa)
Very HighErodibility
I
HighErodibility
IIMedium
Erodibility III Low
Erodibility IV
Very LowErodibility
V
Erosion Rate
(mm/hr)
10
Jean-Louis BRIAUD – Texas A&M University
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CRITICAL VELOCITY CRITICAL VELOCITY vsvs GRAIN SIZEGRAIN SIZE
0.01
0.1
1
10
100
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
Vc = 0.35 (D50)0.45
Vc = 0.1 (D50)-0.2
Vc = 0.03 (D50)-1
US Army Corps of Engineers EM 1601
Jean-Louis BRIAUD – Texas A&M University
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CRITICAL SHEAR STRESS CRITICAL SHEAR STRESS vsvs GRAIN SIZEGRAIN SIZE
0.01
0.1
1
10
100
1000
10000
0.0001 0.001 0.01 0.1 1 10 100 1000 10000
Mean Grain Size, D50 (mm)
Critical ShearStress,
τc
(N/m2)
US Army Corps of Engineers EM 1601
CLAY SILT SAND GRAVEL RIP-RAP
Curve proposed by Shields (1936)
τc = D50
τc = 0.006 (D50)-2
τc = 0.05 (D50)-0.4
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Jean-Louis BRIAUD – Texas A&M University
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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 propertiesErodibility 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 passing #200
Jean-Louis BRIAUD – Texas A&M University
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NO SIMPLE CORRELATION !
CSS vs.#200
R2 = 0.1306
0.00
5.00
10.00
15.00
20.00
25.00
0.00 20.00 40.00 60.00 80.00 100.00 120.00
# 20 0 ( %)
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)
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Jean-Louis BRIAUD – Texas A&M University
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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)
Very HighErodibility
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)
Very HighErodibility
I
HighErodibility
IIMedium
Erodibility III
LowErodibility
IV
Very LowErodibility
V
Erosion Rate
(mm/hr)
Jean-Louis BRIAUD – Texas A&M University
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.
2 2 2
m n pcZ
u u u uτ τ τ σα β δρ ρ ρ
⎛ − ⎞ ⎛ ⎞ ⎛ ⎞Δ Δ= + +⎜ ⎟ ⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠ ⎝ ⎠Mean Net
Shear Stress
Shear Stress
Turbulence
Normal Stress
Turbulence
.( )Z f τ=
Constitutive Law for Soil Erosion
13
Jean-Louis BRIAUD – Texas A&M University
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Input to an erosion problemInput to an erosion problem
••Soil (Erodibility)Soil (Erodibility)
••Water (Velocity)Water (Velocity)
••Geometry (Dimensions)Geometry (Dimensions)
Jean-Louis BRIAUD – Texas A&M University
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Shear Stress Applied by Water
dz
14
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Flow HydrographFlow Hydrograph
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Velocity & Water Depth HydrographVelocity & Water Depth Hydrograph
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Obtaining a design flood valueObtaining 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
Jean-Louis BRIAUD – Texas A&M University
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Probably of Exceedance Probably of Exceedance -- PoEPoE
100 yr 100 yr 53% 53% PoEPoE, , vv100100 = 2.8* = 2.8* m/sm/s500 yr 500 yr 13.9% 13.9% PoEPoE, , vv500500 = 3.25* = 3.25* m/sm/s10000 yr10000 yr 0.75% 0.75% PoEPoE, , vv1000010000 = 3.95* = 3.95* m/sm/s
** Example for Woodrow Wilson Bridge for 75 year design life.Example for Woodrow Wilson Bridge for 75 year design life.
Structural Eng. operate at a Prob. of Exceedance of 0.1%?Structural Eng. operate at a Prob. of Exceedance of 0.1%?Geotechnical Eng. operate at a Prob. of Exceedance of 1%?Geotechnical Eng. operate at a Prob. of Exceedance of 1%?Hydraulic Eng. operate at a Prob. of Exceedance of 10%?Hydraulic Eng. operate at a Prob. of Exceedance of 10%?
17
Jean-Louis BRIAUD – Texas A&M University
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Input to an erosion problemInput to an erosion problem
••Soil (Erodibility)Soil (Erodibility)
••Water (Velocity)Water (Velocity)
••Geometry (Dimensions)Geometry (Dimensions)
Jean-Louis BRIAUD – Texas A&M University
34
PIER SIZE & SHAPE for PIER SCOUR
18
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CONTRACTION RATIO for CONTRACTION SCOUR
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RADIUS OF CURVATURE FOR MEANDERS
19
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WAVE ATTACK FOR CLIFF EROSION
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OVERTOPPING OF LEVEES
20
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RANS EquationsRANS EquationsContinuity equationContinuity equation
Momentum (RANS) EquationsMomentum (RANS) Equations
Energy EquationEnergy 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
Jean-Louis BRIAUD – Texas A&M University
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Reynolds StressesReynolds StressesTransport EquationsTransport Equations
ProductionProduction
Diffusion by uDiffusion by umm
Diffusion by pDiffusion by p′′
Viscous DiffusionViscous Diffusion
PressurePressure--StrainStrain
DissipationDissipation
ijijijv
ijp
iju
ijijm,
mij
DDDPRUt
R εΦ −++++=+∂∂
jn,
im,
mnij
im,
jmjm,
imij
ijmn,
mnijv
m,jim
m,ijmij
p
m,jimij
u
injljnilmlmn
im,
jmjm,
imij
uug2
)ugug)(/'p(
RgD
)/ρ'pu(g)/ρ'pu(gD
)uuu(D
)RgRg(e2
)URUR(P
νε
ρΦ
ν
Ω
=
+=
=
−−=
−=
+−
+−=
21
Jean-Louis BRIAUD – Texas A&M University
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TwoTwo--Layer kLayer k--εε ModelModel•• Outer LayerOuter Layer (Fully Turbulent Region)(Fully Turbulent Region)
( )ρεεεσμμεερ
ρεσμμρ
εεεε
2b31
m,
n,tmn
m,m
b
m,
n,k
tmnm,
m
CPCPCk
gUt
PPkgkUtk
−++⎭⎬⎫
⎩⎨⎧
⎟⎟⎠
⎞⎜⎜⎝
⎛+=⎟
⎠⎞
⎜⎝⎛ +∂∂
−++⎭⎬⎫
⎩⎨⎧
⎟⎟⎠
⎞⎜⎜⎝
⎛+=⎟
⎠⎞
⎜⎝⎛ +∂∂
• Inner Layer (Near-Wall Region)
( )[ ] ( )[ ] AR1yC ;AR1yC
kC ;k
PPkgkUtk
yy
t
3/2
b
m
nk
tmnm
m
εεμμ
μμε
ρμε
ρεσμμρ
/exp/exp
,
,,
−−=−−=
==
−++⎭⎬⎫
⎩⎨⎧
⎟⎟⎠
⎞⎜⎜⎝
⎛+=⎟
⎠⎞
⎜⎝⎛ +∂∂
• Compute wall shear stress directly without wall function approximation
Jean-Louis BRIAUD – Texas A&M University
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( )bb
b
2 2 2
,
0 ,
; q U
b c c
c
b
cZ
q V Wn
τ τ τ τ
τ τ
τ μ
⎧ − >⎪= ⎨≤⎪⎩
∂= = + +
∂
Scour Rate EquationScour Rate Equation
•• Critical shear stress Critical shear stress ττcc
•• Streambed shear stress Streambed shear stress ττbb
•• Both the initiation and termination of scour process Both the initiation and termination of scour process are determined by the critical shear stressare determined by the critical shear stress
•• The scourThe scour--rate vs. shear stress curves are siterate vs. shear stress curves are site--specific and must be determined from the specific and must be determined from the measurementsmeasurements
22
Jean-Louis BRIAUD – Texas A&M University
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23
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1.1.Fundamentals of Soil ErosionFundamentals of Soil Erosion
2.2.Woodrow Wilson BridgeWoodrow Wilson Bridge
3.3.Brazos River MeanderBrazos River Meander
4.4.Normandy CliffsNormandy Cliffs
5.5.New Orleans LeveesNew Orleans Levees
24
Jean-Louis BRIAUD – Texas A&M University
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Woodrow Wilson Bridge and Pier Scour
Jean-Louis BRIAUD – Texas A&M University
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60% of BRIDGE FAILURES60% of BRIDGE FAILURESARE DUE TO SCOURARE DUE TO SCOUR
0
100
200
300
400
500
600
700
800
900
1000
Con
stru
ctio
n
Con
cret
e
Det
erio
ratio
n
Eart
hqua
ke
Nat
ural
Stee
l
Fire
Mis
c.
Ove
rloa
d
Col
lisio
n
Hyd
raul
ic
Cause
Num
ber o
f Fai
lure
s fr
om19
66 to
200
5 (1
502
Tota
l)
0%
10%
20%
30%
40%
50%
60%
Perc
ent
25
Jean-Louis BRIAUD – Texas A&M University
49Schoharie Creek Bridge Failure – 17 April 198710 people died
Jean-Louis BRIAUD – Texas A&M University
50
26
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OldWoodrow Wilson
Bridge
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NewWoodrow Wilson
Bridge
27
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SOIL LAYERS
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STRATIGRAPHY
TO SCALE
NOT TO SCALE
28
Jean-Louis BRIAUD – Texas A&M University
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EFA EFA -- EROSION FUNCTION APPARATUSEROSION FUNCTION APPARATUS
Jean-Louis BRIAUD – Texas A&M University
56Soft organic clay, Low Su (22 kPa)Vc = 0.5 to 2.2 m/s; higher rates
Hard mineral clay, High Su (130 kPa)Vc = 0.2 m/s; lower rates
29
Jean-Louis BRIAUD – Texas A&M University
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Jean-Louis BRIAUD – Texas A&M University
58Obtaining the 100 yr and 500 yr floodObtaining the 100 yr and 500 yr floodFlood-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
Jean-Louis BRIAUD – Texas A&M University
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Jean-Louis BRIAUD – Texas A&M University
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Bascule Pier Layout (M1)Direction of Flow
Pedestal
Arch Rib
39.2
m
26.5 m
1.8 m Dia. open ended steel pipe pile
EL. 4 m (500 yr)EL. 3 m (100 yr)
EL. 0.6 m (Ave.)
EL. -10.5 m (River Bottom)
Estimated Tip EL. -68.6 m
58.1
m5.
9 m
31
Jean-Louis BRIAUD – Texas A&M University
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Bascule Pier with Ring Layout (M1)
Arch Rib
EL. 0.6 m (Ave.)
EL. -10.5 m (River Bottom)
Estimated Tip EL. -68.6 m
Estimated Tip EL. -45.7 m
1.4 m Dia. open ended steel pipe pile
[SECTION A]
A A
Concrete fender ring with composite marine timber facing
Jean-Louis BRIAUD – Texas A&M University
62Hydrograph (Add 500year flood)
0
3000
6000
9000
12000
15000
18000
1960 1970 1980 1990 2000
Time (Year)
Scour Depth Vs. Time (Add 500year flood)
0
2
4
6
8
10
12
1960 1970 1980 1990 2000
Time (Year)
Scou
r Dep
th (m
)
Scou
r Dep
th (m
)Fl
ow (m
3 /s)
32
Jean-Louis BRIAUD – Texas A&M University
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SCALED FLUME TESTS
FHWA
PIER ONLY
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SCALED FLUME TESTS (FHWA)PIER and RING (Final Design)
33
Jean-Louis BRIAUD – Texas A&M University
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0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
HEC-18Sand(Pile
Width)
HEC-18Sand(PileCap)
Salim-Jones
HEC-18Clay
(TexasA&M)
ErodibilityIndex
LargeScaleFlumeTest
SmallScaleFlumeTest
SelectedScour
Scou
r Dep
th (m
Comparison of Scour PredictionsBascule Pier M1 (500yr Flood)
Jean-Louis BRIAUD – Texas A&M University
66
NOT TO SCALENEW BRIDGE WITH STRATIGRAPHY
TO SCALE
34
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PIER 1E
OldWoodrowWilsonBridge
Jean-Louis BRIAUD – Texas A&M University
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35
Jean-Louis BRIAUD – Texas A&M University
69Predicted Hydrograph (75year)
0
3000
6000
9000
12000
15000
18000
0 15 30 45 60 75
Time (Year)
Stre
amflo
w (m
3 /s)
Predicted Scour Depth Vs. Time
0
2
4
6
8
10
12
0 15 30 45 60 75
Time (Year)
Scou
r Dep
th (m
)
Probability of exceedance of a scour depth
0 .0 1
0 .1
1
1 0
1 0 0
5 7 .5 1 0 1 2 .5 1 5
d (m)
R(d
) (%
)
L t= 5 0 ye a rL t= 7 5 ye a rL t= 1 0 0 ye a rL t= 1 5 0 ye a r
Prob
abili
ty o
f Ex
ceed
ance
Scour Depth (m)
Jean-Louis BRIAUD – Texas A&M University
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Static Load Test
36
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StatnamicLoad Test
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Pile for Bascule Pier (M1)EL. 4 m (500 yr)
EL. -68.6 m (Estimated Pile Tip)
12000 kN
618 kNEL. 3 m (100 yr)EL. 0.6m (Ave.)
EL. -10.5 m (River Bottom)
Alluvial Soil
River
Glacial Sand
Cretaceous Clay
Open Ended Steel Pipe Pile (D = 1.8 m, L = 64 m)
13.0 m
45.1 m
M1: Earthquake
M2: Vessel Collision
M3~M10: Wind Load
5.9 m
500 yr scour depth
37
Jean-Louis BRIAUD – Texas A&M University
73Comparison
Soft Clay
Loose Sand
Hard Clay
1.8 m
19.2 m
33 yr scour depth(measured)1.6 m/s velocity
Pile SizeD = 1.8 m, L = 64 m
River
Pile SizeD = 0.5 m, L = 21 m
500 yr scour depth3.2 m/s velocity
13.0 m
45.1 m
5.9 m
[New Pile for Bascule Pier] [Old Pile for Bascule Pier]
154 PILES78 PILES
Jean-Louis BRIAUD – Texas A&M University
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38
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39
Jean-Louis BRIAUD – Texas A&M University
77Demolition of Old Woodrow Wilson Bridge
Jean-Louis BRIAUD – Texas A&M University
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1.1.Fundamentals of Soil ErosionFundamentals of Soil Erosion
2.2.Woodrow Wilson BridgeWoodrow Wilson Bridge
3.3.Brazos River MeanderBrazos River Meander
4.4.Normandy CliffsNormandy Cliffs
5.5.New Orleans LeveesNew Orleans Levees
40
Jean-Louis BRIAUD – Texas A&M University
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Brazos River and MeanderMigration
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FM159
SH105
Navasota
Brenham
198119952006
0 400 (m)
NORTH
41
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PROBLEM = CHANNEL
MIGRATION
1969 1999
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MEASURED CHANNEL MOVEMENT
0
50
100
150
1980 1985 1990 1995 2000 2005 2010
Time (year)
Cha
nnel
Mov
emen
t (m
)
42
Jean-Louis BRIAUD – Texas A&M University
83
BrazosRiver
at SH105
FLOW
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84
Undercutting
Sloughing
Deposition
43
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85
MethodologyFor
Predicting Meander Migration
•Soil erosion function
•Water velocity hydrograph (risk)
•Geometry
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86
Large Scale Flume Tests in Sand
1m
44
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87
Large Scale Flume Tests in Clay
1m
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88
EFA EFA -- EROSION FUNCTION APPARATUSEROSION FUNCTION APPARATUS
45
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89
Numerical Simulations
Jean-Louis BRIAUD – Texas A&M University
90MEANDER GEOMETRY PARAMETERS
R
W
θ
R
φ
φ
A
M(t)
46
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91
MEANDER RESONANCE
(b)
(a)
(c)
R/W
R/W
R/W
(b)
(a)
0 2 4 6 8R/W
M/v
(a)
(b)
(c)
.
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92
Main Screen of MEANDER
47
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Sampling Locations
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94
300
0 100 200 300 400 500 600
1951 Profile2006 Profile(m)
(m)
TO SCALE
To Brenham (West)To Navasota (East)
Erosion
Deposition
1951 Profile2006 Profile
0 100 400200 300 500 600
00
30
20
10
(m)
(m)
NOT TO SCALE
Cross-sectional Profile at Meandering Bend
NORTH
WEST
48
Jean-Louis BRIAUD – Texas A&M University
95
Soil Layers at B-2To Brenham (West)To Navasota (East)
2006 Profile
Hard Brown Clay
Stiff Brown Silty Clay
Very Dense BrownSilty Sand (SM)
IV IIII IIV
ErodibilityCategory
Depth(m)
15.0
13.1
8.0
6.0
0
Very Dense Sand(SP)NORTH
Jean-Louis BRIAUD – Texas A&M University
96
EFA EFA -- EROSION FUNCTION APPARATUSEROSION FUNCTION APPARATUS
49
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97
EFA Test Results: Erosion Rate vs. Shear Stress
0.1
1.0
10.0
100.0
1000.0
0.1 1.0 10.0 100.0Shear Stress (N/m2)
Eros
ion
Rat
e (m
m/h
r)B1-(30-32)
B1-(40-42)
B1-(48-50)
B2-(30-32)
B2-(38-40)
B2-(48-50)
B3-(10-12)
B3-(20-22)
B3-(30-32)
B3-(38-40)
B3-(48-50)
Upper Bound
Low er Bound
Chosen forPrediction
Jean-Louis BRIAUD – Texas A&M University
98
EFA Test Results: Erodibility Categories
0.1
1
10
100
1000
10000
100000
0.1 1.0 10.0 100.0
Velocity (m/s)
Eros
ion
Rat
e (m
m/h
r)
B1-(30-32) B1-(40-42) B1-(48-50) B2-(30-32) B2-(38-40) B2-(48-50)
B3-(10-12) B3-(20-22) B3-(30-32) B3-(38-40) B3-(48-50)
Very HighErodibility
I
HighErodibility
IIMedium
ErodibilityIII
LowErodibility
IV
Very LowErodibility
V
50
Jean-Louis BRIAUD – Texas A&M University
99Water hydrograph
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
June-57 June-62 June-67 June-72 June-77 June-82 June-87 June-92 June-97 June-02 June-07
Time (year)
Dai
ly D
isch
arge
(m3 /s
)
1957 1962 1967 1972 1977 1982 1987 1992 1997 2002 2007
Discharge
0.0
0.5
1.0
1.5
2.0
2.5
3.0
June-57 June-62 June-67 June-72 June-77 June-82 June-87 June-92 June-97 June-02 June-07
Time (year)
Dai
ly M
ean
Velo
city
(m/s
)
1957 1962 1967 1972 1977 1982 1987 1992 1997 2002 2007
Velocity
Jean-Louis BRIAUD – Texas A&M University
100
FM159
SH105
Navasota
Brenham
19811995
2006
0 400 (m)
NORTH
51
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101
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102
52
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103
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104
Highway 105
LegendRiver (Today)
50% Probability that river will reach here or further10% Probability that river will reach here or further1% Probability that river will reach here or further0.1% Probability that river will reach here or further
ProbabilisticPredictionsAt 20 years
53
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105
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106
There is a 1% probability that the river will move There is a 1% probability that the river will move outward outward 23.7m or more23.7m or more..
54
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107
1.1.Fundamentals of Soil ErosionFundamentals of Soil Erosion
2.2.Woodrow Wilson BridgeWoodrow Wilson Bridge
3.3.Brazos River MeanderBrazos River Meander
4.4.Normandy CliffsNormandy Cliffs
5.5.New Orleans LeveesNew Orleans Levees
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108
Pointe du Hoc and Cliff Erosion
World War II Invasion SiteJune 6th, 1944
55
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109
25 APRIL 194413 MAY 194422 MAY 19444 JUNE 19445 JUNE 19446 JUNE 1944
http://b26marauder.com/322nd/b26inflight.html
HEAVY BOMBARDEMENT OF POINTE DU HOC
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110
56
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111CLIMBING THE CLIFFS AT LOCATIONS OF BOMB IMPACT
General Earl Rudder and 200 Rangers
Jean-Louis BRIAUD – Texas A&M University
112POINTE DU HOC TODAY
57
Jean-Louis BRIAUD – Texas A&M University
113Approximately 10 m of erosion since 1945Average cliff erosion rate = 0.167 m/yr
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114
Sandown Bay in Isle of Wight south of UK (2003 ~ 2006) Maximum Wave Height
0
1
2
3
4
5
6
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Max
imum
Wav
e H
eigh
t (m Hmax (m)
58
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115
Fluctuation of high and low tide levelfrom April to September, 2006 at Pointe du Hoc
Tide Levels
01234
5678
1-Apr-06 1-May-06 31-May-06 30-Jun-06 30-Jul-06 29-Aug-06 28-Sep-06
Date
Leve
l (m
)
Maximum daily tide level
Minimum daily tide level
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116
Sketch cross section of the cliff and Observation Post
59
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117
Inside the Observation PostInside the Observation Post
Jean-Louis BRIAUD – Texas A&M University
118Drilling Rig
60
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119
SiltyClay
Fractured Limestone
Very hard Sandstone
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120
STRATIGRAPHY
61
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121
General stratigraphy near Observation Post.
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122
ELECTRICAL RESISTIVITY PROFILES
62
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123
EFA EFA -- EROSION FUNCTION APPARATUSEROSION FUNCTION APPARATUS
Jean-Louis BRIAUD – Texas A&M University
124
0.1
1
10
100
1000
10000
100000
0.1 1.0 10.0 100.0Velocity (m/s)
Eros
ion
Rat
e(m
m/h
r)
Clay-B5-(6.40-7.25m)
Very HighErodibility
IHigh
Erodibility II
MediumErodibility
IIILow
Erodibility IV
Very LowErodibility
V
Silty Clay (surface soil) erosion function50 mm/hr for 1 m/s or 438 m/yr
63
Jean-Louis BRIAUD – Texas A&M University
125
0.0330.0180.024Erosion Rate
(mm/hr)
30.63727.70328.719Shear stress
(Pa)
3.5923.6113.676Velocity(m/sec)
Marly lime-stone
SandstoneLimestone
Rock erosion rates0.025 mm/hr at 3.6 m/s or 0.22 m/yr
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126
Erosion of cliff base
Caverns below the Observation Post
64
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127
CLIFF BASE EROSION
Jean-Louis BRIAUD – Texas A&M University
128Overhang with separation
of the rock block from the rock mass
65
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129
Rock block removal analysis
Jean-Louis BRIAUD – Texas A&M University
130Required Wave Head (Hwave) to Move a Rock Block
0
1
2
3
4
5
6
0 1 2 3 4
Rock Block Size (m)
Wav
e He
ad (m
)
φ=30φ=45
66
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131
FINITE ELEMENT MESH TO OBTAINSTRESSES IN ROCK NEAR CLIFF
Jean-Louis BRIAUD – Texas A&M University
132
0
5
1 0
1 5
2 0
2 5
3 0
-6 0 -4 0 -2 0 0 2 0 4 0 6 0
H o r i z o n ta l S tr e ss (k P a )
Ele
vatio
n fr
om S
ea L
evel
(m)
1 m E ro s io n2 m E ro s io n3 m E ro s io n4 m E ro s io n5 m E ro s io n
C o m p r e ssi o n T e n si o n
Horizontal stress distribution in rock massMaximum tensile stress = 1/10th of intact rock tensile strength
67
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133
TENSILESTRENGTH
TEST
Jean-Louis BRIAUD – Texas A&M University
134
23.633.8324.534.52MarlyMarly LimestoneLimestone
23.151.4823.494.55SandstoneSandstone
24.143.1224.903.36LimestoneLimestone
γγdrydrywwccγγttσσtt
(kN/m(kN/m33))(%)(%)(kN/m(kN/m33))((MPaMPa))SampleSample
AVERAGE TENSILE STRENGTH AND TEST RESULTS
68
Jean-Louis BRIAUD – Texas A&M University
135
L
22m L
H
Pt
t
L
H
22m L
H
Pt
t
P
CANTILEVER BEAM ANALYSIS
Jean-Louis BRIAUD – Texas A&M University
136Massive collapse about 300m west of the Observation Post
Block length (cavern depth or cantilever length) is about 4 m
69
Jean-Louis BRIAUD – Texas A&M University
137Proposed remediation to reopen the Observation Post
Jean-Louis BRIAUD – Texas A&M University
138
1.1.Fundamentals of Soil ErosionFundamentals of Soil Erosion
2.2.Woodrow Wilson BridgeWoodrow Wilson Bridge
3.3.Brazos River MeanderBrazos River Meander
4.4.Normandy CliffsNormandy Cliffs
5.5.New Orleans LeveesNew Orleans Levees
70
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139
New Orleans Levees and Overtopping Erosion
Jean-Louis BRIAUD – Texas A&M University
140
USA BUDGET = 2500 Billion $ / year
Katrina damage = 125 Billion $
Katrina damage = 5% of USA budget / yr
71
Jean-Louis BRIAUD – Texas A&M University
141USA Population = 300,000,000Deaths per year = 2,500,000
Deaths during Katrina = 1500 or 0.06%Cancer = 600,000 / yr or 24 %
20059 5 5 1 9 6 0 1 9 6 5 1 9 7 0 1 9 7 5 1 9 8 0 1 9 8 5 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0
600
01955
DEATHSPER YR AND PER 100,000
Heart Attack
Cancer
Stroke
Jean-Louis BRIAUD – Texas A&M University
142On 29 August 2005, Hurricane Katrina hit the Coast of the Gulf of Mexico
72
Jean-Louis BRIAUD – Texas A&M University
143
Hurricane = 250 miles in diameterHurricane = 250 miles in diameter
Travel speed = 25 mphTravel speed = 25 mph
Time on a levee or a bridge = 10 hoursTime on a levee or a bridge = 10 hours
Number of wave cycles = 6000Number of wave cycles = 6000
Jean-Louis BRIAUD – Texas A&M University
144
Created by friction between the windand the water, a storm surge develops
73
Jean-Louis BRIAUD – Texas A&M University
145STORM SURGE
8.5 m
4.6 m
3.0 m
Jean-Louis BRIAUD – Texas A&M University
146
74
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147
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75
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76
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77
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TO SCALE
NOT TO SCALE
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78
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155
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Flood Return PeriodFlood Return Periodused in design in the Netherlands (levees)used in design in the Netherlands (levees)1/10,000 for most populated areas1/10,000 for most populated areas1/4,000 for less populated areas1/4,000 for less populated areas
Flood Return PeriodFlood Return Periodused in design in the USA (bridges)used in design in the USA (bridges)1/500 with Factor of Safety of 11/500 with Factor of Safety of 11/100 with normal Factor of Safety1/100 with normal Factor of Safety
Overtopping of levees not considered in levee Overtopping of levees not considered in levee design in the USAdesign in the USA
79
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EFA - EROSION FUNCTION APPARATUS
80
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159
0.11.0
10.0100.0
1000.010000.0
100000.0
0.1 1.0 10.0
Shear Stress (Pa)
Ero
sion
Rat
e(m
m/h
r) NO-S-4-LightCompactionDepth(ft):0 - 1D50 = -mm
Jean-Louis BRIAUD – Texas A&M University
160
0.1
1.0
10.0
0.1 1.0 10.0 100.0 1000.0
Shear Stress (Pa)
Ero
sion
Rate
(mm
/hr) S3-B3-(0-1ft)
Depth(ft):0-1Su = 94kPa
81
Jean-Louis BRIAUD – Texas A&M University
161EFA TEST RESULTS EFA TEST RESULTS -- Erosion rate Erosion rate vsvs velocityvelocity
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
Very HighErodibility
I
HighErodibility
II MediumErodibility
III
LowErodibility
IV
Very LowErodibility
V
Erosion Rate
(mm/hr)
Jean-Louis BRIAUD – Texas A&M University
162EFA TEST RESULTS EFA TEST RESULTS -- Erosion rate Erosion rate vsvs shear stressshear 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
Very HighErodibility
IHigh
Erodibility II
MediumErodibility
IIILow
Erodibility IV
Very LowErodibility
V
Erosion Rate
(mm/hr)
82
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163
NUMERICAL SIMULATIONNUMERICAL SIMULATION
Jean-Louis BRIAUD – Texas A&M University
164
t = 0.80 sec
t = 1.28 sec
t = 1.60 sec
t = 1.92 sec
t = 2.39 sec
83
Jean-Louis BRIAUD – Texas A&M University
165SHEAR STRESSES ON LEVEE SURFACESHEAR STRESSES ON LEVEE SURFACE
Jean-Louis BRIAUD – Texas A&M University
166EFA TEST RESULTS EFA TEST RESULTS -- Erosion rate Erosion rate vsvs shear stressshear 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
Very HighErodibility
IHigh
Erodibility II
MediumErodibility
IIILow
Erodibility IV
Very LowErodibility
V
Erosion Rate
(mm/hr)
84
Jean-Louis BRIAUD – Texas A&M University
167
LEVEES LEVEES –– FAILED and NOT FAILEDFAILED 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
Very HighErodibility
I
HighErodibility
II MediumErodibility
III
LowErodibility
IV
Very LowErodibility
V
Erosion Rate
(mm/hr)
Note:- Solid circles = levee breaches- Empty circles = no levee damage
Jean-Louis BRIAUD – Texas A&M University
168
LEVEE OVERTOPPING CHARTLEVEE OVERTOPPING CHART
0.1
1
10
100
1000
10000
100000
0.1 1.0 10.0 100.0
Velocity (m/s)
ErosionRate
(mm/hr)
Very HighErodibility
I
HighErodibility
IIMedium
Erodibility III
LowErodibility
IV
Very LowErodibility
V
TRANSITIONZONE
PRONE TOFAILURE BY
OVERTOPPING
PRONE TO RESIST
OVERTOPPING
85
Jean-Louis BRIAUD – Texas A&M University
169
••Fundamentals of Soil ErosionFundamentals of Soil Erosion
••Woodrow Wilson BridgeWoodrow Wilson Bridge
••Brazos River MeanderBrazos River Meander
••Normandy CliffsNormandy Cliffs
••New Orleans LeveesNew Orleans Levees
Jean-Louis BRIAUD – Texas A&M University
170
•Scour and erosion is a large field of civil engineering (bridge scour, cliff erosion, levee erosion, meander migration, piping in dams, construction sites surface erosion, highway embankment surface erosion, beach erosion).
•Geotechnical engineers need to get involved as the soil and rock side of the field (practice andresearch) is seriously lagging behind the hydraulic side………………………………………….
CONCLUSION
http://ceprofs.civil.tamu.edu/briaud/