incipient motionpierre/ce_old/projects/linkfiles/... · colorado state university, fort collins, co...
TRANSCRIPT
![Page 1: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/1.jpg)
1
Sedimentation Engineering…Incipient Motion and Bedforms
Pierre Y. JulienProfessor of Civil and Environmental EngineeringColorado State University, Fort Collins, CO 80523
January 15, 2008UiTM, Shah Alam, Malaysia
Incipient Motion
![Page 2: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/2.jpg)
2
Shields Parameter• Ratio of
Hydrodynamic Forces to Submerged Weight
( ) ( ) ss
m
ss
o
du
d γγρ
γγττ
−=
−=
2*
*
Beginning of Motion• Critical Shields Parameter(τ*c)
– beginning of motion (τo = τc) ( ) ss
cc dγγ
ττ−
=*
![Page 3: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/3.jpg)
3
Calculating Critical Shear Stress
Bedforms and Resistance to Flow
![Page 4: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/4.jpg)
4
What are bedforms?Initiation of Bedforms on a flat bed
Wind Blown Ripples on Dunes
Antidunes
Ripples
Dunes
Lower Regime - Ripples• Small Grain Diameter
– d50 < 0. 6mm• Manning n
– 0.018 to 0.028• Concentration
– 10 to 200 mg/L• Small Features
– Less than 20 cm long – A few cm high
• Dominant Roughness– Form
Linguoid current ripples Kennetcook River
![Page 5: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/5.jpg)
5
Lower Regime - Dunes• Coarser Grain Diameter
– d50 < 2 mm• Manning n
– 0.02 to 0.04• Concentration
– 200 to 3000 mg/L• Large Features
– Up to tens of meters in height
• Dominant Roughness– Form
• Field Characteristic– Boils on the water surface
Transition - Washed Out Dunes
• Manning n– 0.014-0.025
• Concentration – 1,000 to 4,000 mg/L
• Water Surface Profile– Out of Phase
• Dominant Roughness– Form or Grain
![Page 6: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/6.jpg)
6
Upper Regime - Plane Bed• Manning n
– 0.010 to 0.013• Concentration
– 2,000 to 4,000 mg/L• Water Surface Profile
– Parallel• Dominant Roughness
– Grain
Upper Regime – Antidunes• Manning n
– 0.010 to 0.020• Concentration
– 2,000 to 5,000 mg/L• Water Surface Profile
– In Phase• Dominant Roughness
– Grain
![Page 7: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/7.jpg)
7
Upper Regime – Chutes and Pools
• Manning n– 0.018 to 0.035
• Concentration – 5,000 to 50,000 mg/L
• Water Surface Profile– In Phase
• Dominant Roughness– Variable
Bedform Classification• Bedforms are
classified based on:– Shape– Resistance to Flow
(Energy Dissipation)– Sediment Transport– Relationship between
the bed and water surface Forms of bed roughness in sand channels
(Simons and Richardson 1963, 1966)
![Page 8: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/8.jpg)
8
Based on Transport-Stage Parametervan Rijn, 1984b
Study Area of the Rhine River
![Page 9: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/9.jpg)
9
Field Surveys on the Rhine River
Bedform Profiles
![Page 10: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/10.jpg)
10
Dune Height during the Flood
Manning n during the Flood
![Page 11: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/11.jpg)
11
Resistance to Flow
Sedimentation Engineering
![Page 12: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/12.jpg)
12
Total rainfall of Typhoon Maemi from 9/8/2003 to 9/13/2003)
South Korea
Mangun mountain, South Korea
![Page 13: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/13.jpg)
13
Imha Reservoir, South Korea
Annual average: 3,450 tons/km2/year.
Soil loss maps
![Page 14: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/14.jpg)
14
CSU Watershed Model TREX
Flow Depth [ft] 100 yr Storm
Logarithmic Velocity Profile
o
x
zz
uv ln1
* κ=
![Page 15: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/15.jpg)
15
Turbulent Flow Equations
{{
4444 34444 2143421
3214444 34444 21nfluctuatioturbulent
zzzyzx
viscous
zm
gradientpressure
mnalgravitatioz
convective
zz
zy
zx
local
z
yzyyyxym
my
yz
yy
yx
y
xzxyxxxm
mx
xz
xy
xx
x
zvv
yvv
xvv
vzpg
zvv
yvv
xvv
tv
zvv
yvv
xvv
vypg
zv
vyv
vxv
vt
v
zvv
yvv
xvv
vxpg
zv
vyv
vxv
vt
v
⎥⎥⎦
⎤
⎢⎢⎣
⎡
∂∂
+∂
∂+
∂∂
−∇+∂∂
−=∂∂
+∂∂
+∂∂
+∂∂
⎥⎥⎦
⎤
⎢⎢⎣
⎡
∂
∂+
∂
∂+
∂
∂−∇+
∂∂
−=∂
∂+
∂
∂+
∂
∂+
∂
∂
⎥⎥⎦
⎤
⎢⎢⎣
⎡
∂∂
+∂
∂+
∂∂
−∇+∂∂
−=∂∂
+∂∂
+∂∂
+∂∂
++++++
++++++
++++++
2
2
2
1
1
1
υρ
υρ
υρ
![Page 16: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/16.jpg)
16
Riprap Design
![Page 17: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/17.jpg)
17
![Page 18: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/18.jpg)
18
Hapcheon Re-regulation Dam
South Korea
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100
time (hr)
wat
er d
epth
(m)
Degradation and armouring
40 km
37
39
41
43
45
47
49
0 100 200 300 400 500 600
width (m)
bed
elev
atio
n (m
)
19832003
![Page 19: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/19.jpg)
19
River changes below Hapcheon dam
2004
2007
1983
Before
After
Nakdong River and NREB Unsteady modeling for the upstream of NREB
![Page 20: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/20.jpg)
20
Nakdong River Estuary Barrage
Case-Study:Gupo Bridge during Typhoon Maemi in 2003
![Page 21: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/21.jpg)
21
![Page 22: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/22.jpg)
22
![Page 23: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/23.jpg)
23
![Page 24: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/24.jpg)
24
![Page 25: Incipient Motionpierre/ce_old/Projects/linkfiles/... · Colorado State University, Fort Collins, CO 80523 pierre@engr.colostate.edu January 15, 2008 UiTM, Shah Alam, Malaysia Incipient](https://reader034.vdocuments.mx/reader034/viewer/2022042803/5f447fbb0962d23aca25ff0f/html5/thumbnails/25.jpg)
25
Erosion and River Mechanics Textbooks
Acknowledgments• Dr. Sang Kil Park (PNU)• Dr. Un Ji (Myongji U. )• Hyeon Sik Kim (KOWACO)• Young Ho Shin (KOWACO)• Byungdal Kim (KOWACO)• A.F. Embi (DID-Malaysia)• Dr. N.A. Zakaria (USM)• Dr. A. Ab. Ghani (USM)• Dr. J.Ariffin (UiTM-Malaysia)• James Halgren (CSU)• Seema Shah (CSU)