Test Pipe - 450mm Pipe. 4.3.2. Measurement ..... 4.5 General view of test pipe: D= 450mm ...... where Qw is the f low rate over the weir in m3/s and Hp is the.
OF NEWCASTLE UPON TYNE
UNIVERSITY DEPARTMENT
ENGINEERING
OF CIVIL
I
SEDIMENT
TRANSPORT IN
SEWERS
by AMINUDDIN
GHANI
AB.
LIBRARY
NEWCASTLE UNIVERSITY ---------------------------093 51137 3 ---------------------------ýhe5 is LS tS2.
Thesis
submitted
Degree
of
in
Doctor
fulfilment of
of
Philosophy November
the in
1993
requirements Civil
for
Engineering.
the
ABSTRACT
Sewers have been designed of self-cleansing on the concept where deposition. to move continuously sediments are expected without deposition Due to the intermittent nature of the flow, of solids in sewers flows low especially at could occur still such as during flow. flow the receding or dry weather in sewers The study therefore movement will of sediment need to (no-deposition) both loose (some deposition) cover and rigid boundary The present the available conditions. study extended (clean data in rigid boundary to include the conditions pipes) A complimentary of roughness and pipe effects surface size. deposits (pipes deposited study on the effect of sediment with beds) was also carried out. load Extensive transport experiments on bed of non-cohesive deposition in pipe sediments without were carried out channels 154mm, 305mm and 450mm dia. of flow covering wide of -ranges (0.15 depths (0.46 < ya/D < 0.80), sediments < dso (mm) < 8.3) and different bed roughness (0.0 three values < ko (mm) < 1.34). data Supplementary loose beds were on transport over collected in a 450mm dia. bed thicknesses channel with various up to 23% diameter. of pipe New
transport based equations involved in on all variables the derived. Extensive were process from uses of data other relevant The combination were studies made. data of the present and other for both loose boundary rigid in pipes and conditions produced be applicable equations which could over wide range of conditions in sewers. A complimentary bed study on the rigid rectangular channels was also carried out.
Using derived the newly equations, appraisals concept of constant velocity criterion were inadequacy show the the design of present diameters, larger 300mm. than
of the made. practice
traditional The results for pipe
The comparisons derived the made between newly for equations boundaries rigid in pipes and loose that suggest be sewers can designed inverts for diameters with clean up to 1.0m while sewers larger diameters with be designed should for allowing an "optimum" depth deposits. Design of sediment based on the charts derived newly equations were devised.
i
ACKNOWLEDGEMENTS
I
like
also
thank
to Also,
criticism.
Many thanks for
for
the
I wish P. M
Brown
thanks
of to
to
Mr.
R.
help
Payne
to
Special
acknowledgements fellowship the
Newcastle
I
to
at
during
the
course
for also
,
study to
Mr.
their
Willoughby
its
using
R. W. P May, advice
to
wish
and
express
who
University
made
my parents,
and moral this
this
Wal 1 ingford
many
were
always
Malaysia
Sains for
possible
me to
come
for to
research.
Salbiah, of
R.
due to
that
to
my wife,
I.
are
encouragement
acknowledge
Mr.
I
P. Dawber
laboratory.
the
this
conduct
am deep lyA gratitude
providing
and
HRL.
(HRL)
thanks
Escarameia
at
and Mr.
of
my grateful
University
Newcastle.
Ltd.
part
Roorkee
of
Newcastle.
at
Research
M.
Raju
Jefferson
A.
undertaking
my stay
me
J.
made
were
Chalmers to
visits
constructive
study
Ranga of
laboratory
the
Mrs.
willing
providing
Mr.
extend
and
during
supervision
their
Hydraulics
to
opportunity
facility. Mrs.
in
indebted
I am also
K. G.
his
this
to
Perrusquia
during
assistance
for
Novak
Professor G.
time
period.
contributions
due to
also
are
their
P.
Dr.
and
Sweden
Technology,
Professor
with
India
University,
study
valuable
discussions
through
the
of
his
of
provision
generous
and
duration
the
throughout
of
supervisor
my
encouragement,
guidance,
I
to
grateful
very
am
his
for
Nalluri
C.
Dr.
for study.
11
brothers
support. her
patience
and
Finally, and
sisters I sincerely understanding
for
TABLE OF CONTENTS Page ABSTRACT ii
ACKNOWLEDGEMENT TABLE
iii
OF CONTENTS
vii
LIST
OF FIGURES
LIST
OF TABLES
LIST
OF PLATES
LIST
OF MAIN SYMBOLS
1.
INTRODUCTION
1
1.1
Background
1
1.2
Scope
1.3
Outline
2.
3.
xv xviii
xix
Present
of
of
The
NATU RE OF SEDIMENTS
2.1
Background
2.2
Characteristics
Thesis
3
IN
6
SEWERS
6
Earlier
2.2.2
Recent
2.3
Classification
2.4
Modes
2.5
Hydraulic
2.6
Current
8
3.2
Incipient
Sediments Transport
Roughness
Design
Background
7
Studies
Sewer
3.1
Sediments
7
of
OF RELEVANT
of
studies
Sediment
of
Quantity
and
2.2.1
REVIEW
3
Study
Criteria
and
Sewers
14 15 16 18
LITERATURE
22
22 Motion
23
iii
3.3
Sediment 3.3.1
Transport Studies
3.3.2
Transport in Pipes Transport
3.3.3 3.4
4.
Transport
Introduction
4.2
Experimental
Deposited
in
Test
Work
Bed
Studies
Channels
Non-Circular
4.2.2 4.2.3
Flow
Characteristics Supply and
Work
at
Discharge
450mm Pipe Techniques
Sediment Sediment
Characteristics Supply and
Transport Transport
Deposition without Loose Beds over
Resistance
Clean
Pipes
5.1.2
Pipes
with
Discharge
Uniform Flow Experimental
ANALYSES
5.1.1
(HRL)
HR Wallingford
Establishment of Sediment Transport 4.3.5.1 4.3.5.2
PRELIMINARY
Sediment Sediment
Test Pipe Measurement The Sediments
4.3.3.1 4.3.3.2 4.3.4 4.3.5
Pipe Pipe
Artificial Roughening of the 305mm Pipe Establishment Flow of Uniform Sediment Transport Experimental Procedure
Experimental 4.3.1 4.3.2 4.3.3
154mm 305mm
Techniques Measurement The Sediments 4.2.3.1 4.2.3.2
4.2.4 4.2.5 4.2.6
(UNUT)
Newcastle
at
Pipes
4.2.1.1 4.2.1.2
5.1
over
Deposition
of
APPARATUS AND PROCEDURE
4.1
4.2.1
5.
Limit
Summary
EXPERIMENTAL
4.3
the at in Pipes
Deposited iv
Beds
Procedure
5.2
5.3
Sediment 5.3.1 5.3.2 5.3.3 5.3.4 5.3.5 5.3.6 5.3.7
6.
ANALYSES 6.1
Experimental Roughness
Clear-Water Pipe Wall
Clean 6.1.1 6.1.2 6.1.3
OF
Experimental
Transport Effect Effect Effect Effect Effect Effect Friction
of of of of of of
Results
Background Appraisal Bed Load
of Existing for Models Introduction
6.1.3.2 6.1.3.3
Proposed Sediment Transport Equations Application (1991) Equation of Ackers to Clean Pipes Application (1991) of El-Zaemey Equations to Clean Pipe Bed and Rigid Rectangular Channels
with
6.2.1
Background
6.2.2 6.2.3
Appraisal Bed Load
6.3.2.1 6.3.2.2 6.3.3
Proposed
Design
of
Clean Pipes
Equations Pipes with
Sediment
Deposited
Transport
Beds
Equations
Design
Sewer
General Assessment
Channels
Beds
of Existing for Models
for
Implication 6.3.1 6.3.2
Introduction Clean Pipes Rigid Bed Rectangular
Deposited
6.2.3.1
6.3
Equations Clean Pipes
6.1.3.1
6.1.3.4.1 6.1.3.4.2 6.1.3.4.3
Pipes
DATA
Pipes
6.1.3.4
6.2
Results
Sediment Concentration Flow Depth Sediment Size Roughness Wall Pipe Size Deposit Sediment Sediment Factor with
TRANSPORT
SEDIMENT
-
the
Constant
Pipes Deposited with
Charts
264
Velocity
Loose
Criterion
Beds
264 264 264 268 271
V
7.
CONCLUSIONS AND RECOMMENDATIONS
275
7.1
275
Conclusions 7.1.1 7.1.2 7.1.3
7.2
(Rigid Clean Pipes Pipes Deposited with Design Implications
Recommendations
for
Further
Boundary) Beds (Loose
Research
REFERENCES BIBLIOGRAPHY APPENDICES A. B. C.
Clear Water Data Experimental Transport Sediment Experimental Data Cross-Sectional Geometry of Pipes
Vi
Boundary)
275 278 280
281
LIST
OF FIGURES Page
Figures
2.1
2.2
2.3
2.4
Detailed (After
view of gradual 1992) Verbanck
Effect (After
operation of cleaning 1992) Verbanck
(After 2.5
2.6
trend
Long-term
invert 1992)
on the sediment (After Verbanck
Build-up of trunk sewer
Laplace
Longitudinal
of
profile
(After
Laplace
Typical (After
particle Ashley et
on
deposited 12
13
present
to
Nalluri
present
design
practice
due
to
Ackers
3.2
Incipient Eqn. 3.4
motion (After
Durand's pipe-full
(1953) flow
Bed-load pipe-full
function transport (After flow Craven
3.7
3.8
3.9
3.10
3.11
d iagram
(After
Graf
Functional relationship boundary rigid channels Excess alluvial
functional
channels
(After
28
31 with
beds:
deposited
31
flow
part-full
clean
pipes
at
of 1982)
deposition
for
in
clean
part-full
for suspended (After Arora
for
relationship
Paul-Sakhuja
vii
1990)
circular 1975
36
part-full 38
load et al
rigid
in
transport 1984)
for total-load transport mobility model (After Ackers 1973) channels - White
Bed-load
for
deposition
bed-load in transport (After Novak - Nalluri
limit at Macke
model (After
of
channels
34
for Shear criterion stress flowing channels part-full load pipes
21
34 for
function 1956)
limit
for pipes 1953)
for
21
25
boundary rigid 1975)
criterion a t the (After 1984) Graf
Bed-load transport (After flow Laursen
(1984)
1984)
for criterion Novak - Nal luri
function Bed-load transport (After 1953) Ambrose pipes
Suspended flows in
(1985)
due
Shields
3.6
13 practice
3.1.
3.5
inverts
sewer
design
Appraisal
3.4
in
found sizes al 1992)
2.8
3.3
depth
sediment
Appraisal
of
deposition
sediment
12
2.7
of
10
1992)
al
et
10
1992)
al
et
main
build-up
sediment
volume
of
Brussels
of
in
43 wide 45
boundary 55
3.12
Loveless'
3.13
Effect (After
3.14
3.15
3.16
(1991)
deposits of sediment 1953) Ambrose 3.60
Verification of EQn. (After Nalluri-Kithsiri
Plots
non-circular Test
4.2
Sediment
4.3
Test (After
for
of (p -$
4.1
on
arrangement
capacity
(1990)
data 64
for
other 1992)
load
rectangular
in
154mm -
D=
circular 1968)
Graf-Acaroglu
Newcastle:
channel 64
transport
(After
at
transporting
Kithsiri's
with 1992)
total
channels
flow
56
3.60 of Eqn. Nalluri-Kithsiri
Verification (After data
52
channels
experimental
and
71
305mm
77
sizes Research
Hydraulics
at
arrangement May
66
Ltd:
450mm
D=
85
1993)
4.4
Sediment
sensor
4.5
Sediment
discharge
5.1a
Cross-sectional
geometry
for
clean
pipe
5.1b
Cross-sectional
geometry
for
pipes
with
5.2a
Clear-water
friction
factor
in
a smooth
154mm dia.
pipe
104
5.2b
Clear-water
friction
factor
in
a smooth
305mm dia.
pipe
104
5.2c
Clear-water
friction
factor
in
a smooth
450mm dia.
pipe
105
5.3a
Clear-water (Roughness
friction 1)
factor
in
a rough
Clear-water (Roughness
friction 2)
factor
5.3b
5.4
(After
May
calibration
Validity of the (D = 4R) data
89
1993)
91
curve
99 deposited
beds
305mm dia.
99
pipe 105
in
305mm dia.
a rough
pipe 106
Colebrook-White's
Eqn.
5.6
for
present 106
5.5a
Effect
of
flow
depth
5.5b
Effect
of
flow
depth
5.5c
Effect
of
flow
depth
5.5d
Effect
of
flow
depth
5.6a
Effect
of
particle
size:
flow
depths
up
5.6b
Effect
of
particle
size:
flow
depths
more
-
dso = 0.46mm
111
-
d50 = 1.0mm
111
-
d50 = 2.0mm
112
-
dso = 5.7mm
112
viii
to
half-full
than
half-full
113
113
5.7a
5.7b
5.8a
5.8b
roughness of wall half-full) depths to up
Effect (Flow
dso 1.0mm roughness = of wall half-full) depths more than
Effect (Flow
roughness of wall depths up to half-full)
Effect
(Flow 5.9a 5.9b
5.10a
5.10b
roughness
depths
Effect
-
d50 = 2.0mm
117
depths
Effect (Flow
d50 4.2mm = of wall roughness depths more than half-full)
Effect (Flow
of wall roughness depths up to half-full)
Effect (Flow
d50 5.7mm = of wall roughness half-full) depths more than
5.12a
Definitions
of
pipe
half-full)
of
mean
Definitions features
of mean (Continuous
sediment dunes)
5.14
Increase (Smooth
deposits
in friction pipes)
factor
in
(Rough
119
bed
bedform
and
thickness
bedform
and
122 122 at
limit
of-deposition 124
friction
factor
limit
at
of
deposition
124
pipes)
Friction
5.17
Effect'of Froude number deposited beds with
on
5.18
Effect
Froude
number
on
the
5.19
Effect of Froude bed sediment
number
on
flow
factor
of
6.1a
Predicted
6.1b
Discrepancy dimensionless
Predicted
thickness
bed
5.16
6.2a
119
121
sediment
Increase
d50 = 5.7mm
sediment
dunes)
of
118
121
(Separated
Effect
118
size
features
5.13
117
d50 = 2.0mm
(Flow
to
116
dso 4.2mm = -
roughness up
116
half-full)
more than
of wall
Effect
5.15
wall
of
5.11
5.12b
d50 = 1.0mm
Effect (Flow
C,
at
using
and
limit
the
of
flow
overall
deposition
126 in
resistance
pipe 126
bed
friction
factor due
resistance
128
to 128
Laursen's
for ratio particle
Cv using
beyond
Eqn.
Laursen's size
Novak-Nalluri's ix
3.11
Eqn.
134 3.11
as
a function
of 134
Eqn.
3.15
136
6.2b
Discrepancy function of
6.3a
Predicted
6.3b
Discrepancy dimensionless
for ratio particle
Predicted
6.4b
Discrepancy dimensionless, Predicted
6.5b
Discrepancy dimensionless
6.6a
Predicted
6.6b
Discrepancy
Mayerle's
C,, using
6.4a
6.5a
for Novak-Nalluri's ratio dimensionless particle
for ratio particle C. using
for ratio particle
for
ratio
Eqn.
Macke's
Eqn.
velocity
criterion
-
Eqn.
6.9
Friction
factor
with
sediment
(Combined
data)
6.10
Transport
capacity
criterion
6.11
Transport
capacity
criterion
6.12
Excess velocity criterion (Combined Eqn. 3.35 data)
3.17
as
function
a
of
(All
(Combined
6.13
model
-
data)
present
data)
150 156
6.16
Eqn.
158
of critical data present
6.15
Excess velocity criterion (Combined Eqn. 6.28 data)
-
Excess velocity criterion (Combined 6.29 Eqn. data)
-
particle
ratio flow
160
-
Eqn.
6.22
(Combined
data)
163
6.26b
with
Novak-Nalluri'
s 167
incipient
criteria
for
data)
for
Incipient
ratio
(Combined
incipient
6.14
motion
6.19
for velocity - Eqn. 6.28
critical data
-
-
Eqn.
Eqn.
-
Interpolation of from the combined
Discrepancy proportional
of 142
6.2
Limiting
6.17b
a function
as
142
6.8
dimensionless
of
size
particle
-
Discrepancy
a function
as
3.17
Eqn
6.17a
3.35
141
criterion
6.16
137 139
3.19
velocity
6.13b
of
141
Limiting
Interpolation from entire
a function -
3.19
6.7
6.13a
as
139
Eqn.
Macke's
C,, using
dimensionless
May's size
3.34
Eqn.
Eqn.
May's
137
3.35
Eqn.
Mayerle's size
136
3.34 Eqn.
Mayerle's
C. using
as a
size
Eqn.
Mayerle's size
3.15
Eqn.
velocity Eqn. 6.29 for
169 motion 169
clean
Eqn.
motion
170
pipes
6.31b
with
author's 174
Eqn.
6.33b
with
author's 175
Eqn.
6.13
as
a function
size
for Eqn. depth
of179
6.13
as a function
of 179
X
6.17c
Discrepancy ratio volumetric observed
for
6.17d
Discrepancy ratio velocity observed
for
6.18
Predicted 305mm dia.
6.19
6.20
6.21
6.22
6.23
6.24 6.25
6.26
6.27
6.28
6.29
6.30a
6.30b
Eqn. 6.13 as a function concentration sediment
of
a function
of
6.13
Eqn.
as
for
3.29 Eqn. Ackers' C,, using (W, data = 10dso) pipe
180
180 smooth
author's
184
Ratio of computed particle
measured by Ackers' for size
to critical total mobility Eqn. 3.30 as a function 305mm dia. smooth author's
mobility of dimensionless data pipe
185
Ratio of computed particle
measured by Ackers' for size
to critical total mobility Eqn. 3.30 as a function 305mm dia. smooth author's
mobility of dimensionless data pipe
185
Comparison boundaries
of
incipient
motion
criteria
for
loose
and
187
total Ratio of measured by Novak-Nalluri's computed dimensionless particle dia. pipe data
to critical mobility mobility Eqn. 3.5 as a function of for 305mm size author's smooth
total Ratio of measured by Novak-Nalluri's computed dimensionless particle dia. pipe data
to critical mobility mobility Eqn. 3.5 as a function of for 305mm size author's smooth
Verification data with 'Verification data with
188
188
Ackers'
of modified W. = 1050
Ackers' of modified W. = 1050 or 0.12D
Verification (1988) data
of
modified
Ackers'
Verification (1989) data
of
modified
Ackers'
Verification (1991) data
of
Limiting equation
equation
for
equation
for
equation
for
equation
for
all
present
all
present
191 193
Mayerle 194
May et
al 195
Ackers'
modified
for
equation
Loveless 195
velocity (Combined
due
criterion data)
to
modified
Ackers' 197
of
for ratio dimensionless
Ackers' modified particle size
Discrepancy function of
for ratio proportional
modified flow
Discrepancy function
rigid
xi
Ackers' depth
equation-as
a 201
equation
as a
201
6.30c
6.30d
6.31
6.32
6.33a
6.33b
6.33c
6.33d 6.34 6.35 6.36
6.37
6.38
6.39
6.40
6.41
6.42
ratio
function
limiting
of
Validity of (b = 0.5D)
Eqn.
Validity Loveless'
a
as
equation
202
concentration
for modified ratio limiting velocity 6.37
for
Ackers'
Mayerle's
for of Eqn. 6.37 data clean pipe
clean
202
data
pipe
May et present, (b = 0.5D)
a
as
equation
208 and
al
208
Discrepancy (Eqn. 6.38)
b=0.5D for E1-Zaemey's Eqn. 6.37 with ratio size particle of dimensionless as a function
Discrepancy (Eqn. 6.38)
for Eqn. El-Zaemey's ratio of proportional as a function
Discrepancy (Eqn. 6.38)
b=0.5D for E1-Zaemey's Eqn. 6.37 with ratio size of dimensionless particle as a function
Discrepancy (Eqn. 6.38)
for Eqn. E1-Zaemey's ratio of proportional as a function
Validity (b data
3.57
of Eqn. = 0.5D)
for
Modification Mayerle's
of rough
E1-Zaemey's bed rigid
Modification Mayerle's
of smooth
E1-Zaemey's bed rigid
Modification Mayerle's
of rough
El-Zaemey's bed rigid Eqn. =
Validity channels'
for of Eqn. 6.37 (D = 1.35b) data
Validity
of
Eqn.
Discrepancy or
Eqn.
6.37
Eqn. (D
ratio
6.40 6.40
6.37 Eqn. rectanular 6.37 Eqn. rectanular
= for
ratio
for
for application (D channels
=
for application (D = channels
Mayerle's
to 1.5b)
219
to 1.5b)
219
rectangular
smooth
221
Mayerle's
rough
rectangular 221
rectangular
smooth
other
223
for
rough
other
rectangular
1.35b)
223
of
dimensionless
E1-Zaemey's
a function
of xii
6.37
Eqn.
El-Zaemey's
as a function as
al's
218
for
Discrepancy
May et
and
212
for to Eqn. 6.37 application (D = 2.0b) channels rectanular
Application of Eqn. 6.37 (D = 1.35b) data channel
(D
data
b=0.5D with depth flow
212
218
for
data
211
for to application (D = 2.0b) channels
Eqn. 6.37 rectanular
6.37 1.35b)
of
6.37
b=0.5D with depth flow
211
214
of E1-Zaemey's bed smooth rigid
Application channel
6.37
Mayerle
present,
Modification Mayerle's
or 6.43b
Ackers'
modified
Discrepancy function of
channels' 6.43a
for
Discrepancy
Eqn.
aspect
6.37
ratio
with
D=1.35b
particle with
size
227
D=1.35b 227
6.43c
6.43d
6.44
Discrepancy 6.40 or Eqn.
ratio as
a
Eqn. for E1-Zaemey's limiting function of
6.37 with D=1.35b concentration
228
a
for Eqn. E1-Zaemey's limiting function of
6.37 with velocity
228
Discrepancy 6.40 or Eqn.
ratio as
Validity. rectangular
for 3.57 Eqn. data channel
of
Predicted
6.45b
Discrepancy
function
for
ratio
of
230
6.46b
for Ackers's Discrepancy ratio depth sediment of proportional
6.47a
6.47b
for Discrepancy ratio from effective computed sediment proportional Predicted
6.48b
Discrepancy proportional
6.49a
for ratio sediment
C,. using
Predicted
6.50b
a function
as
237 3.29
with
Cv
observed
239 C,, of
with observed as a function
239 240
3.46
Eqn.
May's depth
Eqn.
3.46
as
function
a
of 240
Discrepancy
for
ratio
3.55
Eqn.
bed
with
242
as
C. using factor
Predicted friction
a function
Perrusquia's
3.55
Eqn.
with
242 overall
243
plot
for
all
present
6.52
4-$
plot
for
the
combined
6.53
Bed-load (Combined
for
pipes
ratio
proportional
243
.-$
Discrepancy concentration
of
utilising
for 3.55, Perrusquia's Eqn. utilising factor as a function of proportional
Discrepancy ratio friction overall depth sediment
model data)
3.55,
Eqn.
Perrusquia's
6.51
6.54a
3.29
Eqn.
Perrusquia's
factor, bed friction depth sediment 6.50a
237
factor
friction 6.49b
May's
C,, using
6.48a
235
Eqn. 3.29 discharge,
Ackers' flow bed
a
3.29
Eqn. C,, using Ackers' discharge from effective
Predicted computed
as
depth
Eqn.
Ackers's
Predicted
3.64
Eqn.
sediment
6.46a
235
3.64
Eqn.
Graf-Acaroglu's
proportional
C. using
Kithsiri's
and
Graf-Acaroglu's
C. using
6.45a
Mayerle
D=1.35b
data
246
data
with
246
deposited
beds
-
Eqn.
6.44 249
for
Eqn.
6.44
as
a function
of
sediment 252
xiii
6.54b
6.54c
Discrepancy proportional
for ratio sediment
Discrepancy
ratio
bed
sediment
for
to
width
Discrepancy dimensionless
for ratio particle
6.54e
Discrepancy
ratio
6.55
Bed-load models (Combined data)
6.54d
6.56a
6.56b
6.56c
Eqn. 6.44 depth
for
Eqn.
6.44
flow
depth
for
ratio
Discrepancy proportional
for ratio sediment for to
Discrepancy ratio bed width sediment
Eqn. 6.46 depth
6.56e
Discrepancy
ratio
6.57
friction factor Composite data) beds (combined
6.59 6.60
6.62b
6.62c
6.63
6.64
function
a
as
of
beds
a function
velocity
- Eqn. of
254
6.56 256
sediment
for
as
a function
of 259
Eqn. 6.46 size
as
Eqn.
as a function
6.46 model
a function
of 260 of 260
for
pipes
of with
velocity
261
deposited 263
ko = O. Omm)
267
Q-S-D plot - dso = 1.0mm (CV = 50ppm, yo/D = 0.5,
ko = 0.6mm)
267
y1/D
= 0.01)
270
= 0.5,
yg/D
= 0.1)
270
Optimum sediment (Cv = 50ppm, Y/D
depth: = 0.25)
d30 = 1.0mm
Optimum sediment (C = S0ppm, Y/D
depth: = 0.50)
dso = 1. Omm
Optimum sediment (Cv = 50ppm, Y/D
depth: = 0.75)
dso = 1.0mm
Q-S-D
plot
= Soppm,
Q-S-D (C
6.62a
253
dso Q-S-D plot 1.0mm = (CV = 50ppm, y, /D = 0.5,
(C 6.61
of
6.46 as a function depth ratio
Eqn. flow
for ratio particle
6.58
as a function
259
Discrepancy dimensionless
6.56d
of
253
deposited
6.46
Eqn.
function
a
ratio
as
with
pipes
Discrepancy concentration
as
6.44
Eqn.
of 252
Eqn. 6.44 size
for
function
as 'a
plot
= S0ppm,
-
Y/D -
Design charts (Cv = S0ppm,
Design
charts
(Cv = 50ppm,
d30 =
1.0mm
= 0.5,
d50 = 1.0mm Y/D
272
272
273
for clean pipes dso = 1.0mm, ko = 0.6mm)
for
pipes
d30 = 1. Omm)
with
Xlv
deposited
274
beds 274
OF TABLES
LIST
Page
Table
2.1
Sediment
characteristics
Pipe-full
2.3
Additional'roughness. (after Henderson
2.5 3.1
for
k-values
2.2
2.4
in
Constant
due
Shields'
sewers
(after
joint
to
criteria criteria
curve
(after
Van Rijn
3.2
3.3
Values
3.4
Suggested in circular
for values channels'
3.5
Values
transport
coefficient
Experimental
4.1
Sediment
4.2
Average'values
works
= 305mm)
clear-water
ranges
for
transport
5.3
Flow
resistance
beds .
(D = 450mm,
pipe 6.5
108
data deposited
with
pipes
-
for
parameters
82 102
127 in
transport
sediment
clean 130
ranges ratio
-
All (Fr.
different
-
All 133
present )
equations
for
Eqn.
data 6.2
(Clean
pipes)
All
present
-
data
Transport relationships
pipe
dso = 0.72mm)
(C) for Discrepancy ratio (Clean data pipes) present
Discrepancy
roughened data
characteristics:
Characteristic channels pipe
6.4
58
bed
68
an artificially
ranges
Experimental
Parameter
a loose
for
3.46)
channels
for
5.2
6.3
Eqn.
76
ko for
of
Experimental
6.2
circular
3.41
Eqn.
54
(May's
over
47
characteristics
5.1
6.1
in
for
3.29
Loveless'
of
q
pipes
3.20)
41 Eqn.
application
in
24 S"_(Egn.
Ackers'
parameter,
transport
3.6
(D
for
19
1984)
transport Values parameter, of May's in transport pipes clean sediment
sediment
17
1987)
CIRIA
17
19
stress
of
1984)
Henderson
eccentricity
(see
shear
of
9
1987)
CIRIA
1984)
velocity
Constant
pipe
sewers
(see
147 clean
150 equations for
based on modified data present entire
xv
functional 152
6.6
Ranges
6.7
Discrepancy
(Clean 6.8
6.9
6.11
6.12
6.13
6.14
6.15
6.17
6.18
ratio
ratio
(Cv)
Discrepancy ratio (Clean pipes)
(Cv)
6.19
Eqn.
for
-
Combined
-
Combined
-
Combined
data 158 data 160
163 3.5
Eqn.
166 for
(Cv)
6.26b
Eqn.
using
Excess motion's
velocity Eqn.
equations 6.29
using
data
Combined
-
167
interpolated
incipient 171
(Cv)
ratio
data
Novak-Nalluri's
using
equations 6.28
Discrepancy
6.22
Eqn.
velocity Eqn.
interpolated
incipient 172
for
6.31b
Eqn.
-
Combined
-
Combined
data 174
pipes)
(Cv)
Discrepancy ratio (Clean pipes)
Selection of the best (Combined clean pipes Discrepancy
(Fr,
ratio
parameters
6.20
Verification pipe clean
6.24
for
Excess motion's
of
Verification
-
measured of data of
for
model data)
for
)
Eqn.
for
Combined
width
of
6.13
in
of data
modified
functions
of
pipes)
178
(W1)
183
spread
equation
for
present 191
Ackers'
Verification pipe clean
as
(Clean
data
sediment
(W. = 1Odso or
Discrepancy Combined
175 transport
sediment
Ackers' modified (W. = 10d30) modified
data
176
data
of effective equation
6.33b
Eqn.
pipe
Values Ackers'
6.16
Eqn.
criterion motion
Discrepancy ratio (Clean pipes)
Values
6.23
data
Combined
-
pipes)
Excess velocity for incipient
clean
6.13
Eqn.
156
Discrepancy
6.19
6.22
for
(I. ) for
relevant
6.21
)
(Fr,
154
pipes)
pipes)
(Clean
6.16
parameters
(Clean
data
combined
Discrepancy ratio (Clean pipes) (Clean
6.10
of
for
equation
for
present
0.12D)
Ackers'
193
equation
for
other, 194
(We) to
width
be
used
in
the
modified 196
(Fr. ) for ratio (Clean data pipes)
xvi
modified
Ackers'
equation
197
6.25
6.26
6.27
6.28
(Fr, ) for Discrepancy ratio (Clean data Combined pipes) (Fr, Discrepancy ratio functions of relevant (Clean pipes) Discrepancy
ratio
(Clean
pipes)
6.29
Ranges
of
6.30
Discrepancy (Rigid bed
6.31
6.34
6.35 6.36
6.39
6.40
bed
rigid
) for Eqn. channels)
(Frs) -
for
rectangular
6.40
-
(Rigid
data
Combined
as 210
214 channels
parameter beds)
222 of
bed
226
for
the
Discrepancy
ratio
(Fr,
Eqn.
parameters
-
beds)
(Fr,
ratio
(Pipes
deposited
)
for
Combined ) for
Eqn.
6.44
(Pipes
6.44
data
Combined
-
All 234 with
data 249
functions
as
(Pipes
6.46
of
with
(Fr, -
Combined
-
beds)
data
256
) for 6.46 as functions Eqn. data (Pipes Combined with
of 258
(A. ) for Eqn. ratio deposited beds)
used for criterion
data
-
230
251
Discrepancy
Discrepancy (Pipes with
equations beds)
-
247
Eqn.
Discrepancy ratio relevant parametres deposited beds)
Eqn. 3.57 channels)
combined
(Fr1, ) for ratio deposited beds)
with
217
data
functions
as
207
data
Combined -
6.40
Eqn.
Discrepancy (Pipes with
Equations velocity
6.38
Eqn.
- Combined
(C) for different Discrepancy ratio (Pipes data deposited with present Range of deposited
200
channels)
deposited
6.38
6.39
Eqn.
(Is) for E1-Zaemey's Discrepancy ratio (Rigid bed rectangular data Combined
relevant
6.37
for
for
parameters
rectangular
6.33
(1Q)
(Fr. ratio rectangular ratio
E1-Zaemey's
as
equation data
) for E1-Zaemey's Eqn. 6.38 data Combined parameters -
parameters
Discrepancy relevant
6.32
) for Ackers' modified Combined parameters -
(Fr, Discrepancy ratio functions of relevant (Clean pipes)
the
appraisals
6.48
-
Combined
data 263
of
the
constant 265
xvii
LIST
OF PLATES Page
Plate 4.1
General
view
of
test
pipe:
D=
154mm
72
4.2
General
view
of
test
pipe:
D=
305mm
73
4.3
Sediment
4.4a
Roughness Pipe wall roughness: (sand d50 = 0.5mm) size
1
Pipe wall Roughness roughness: (sand d30 = 1.0mm) size
2
4.4b
4.5
General
4.6
Sediment
supply
view
of
channel
79
system
test
pipe:
D=
81
81 450mm
86 93
return
xviii
Cross-sectional
A As
of
the
of
the
area
Cross-sectional
area
b
cemented
B
Water
C
Concentration,
Cp
Drag
coefficient
CL
Lift
force
C,
Volumetric
d
Particle
SYMBOLS
OF MAIN
LIST
flow sediment
bed width,
sediment
bed channel
rectangular
width
width
surface
in
constant
Ackers'
equation
coefficient concentration
sediment size diameter
d50
median
D
Internal
diameter
Dh
Hydraulic
depth
Dgr
Dimensionless
Fgr
Mobility
Fr
Flow
Fra
Modified
FS
May's
g
Gravitational
Ggr
General
Ga
Bed load
transport
limit
deposition
particles
of
pipe
of (=
number
d5ß (g(S$-1)/y2
(=
in
Ackers'
(=
(BV2 /gA )0'S )
for
parameter
)1/3)
equation
V/ (gd50
(=
number
mobility
channel
number
parameter
Froude
a mixture
A/B)
particle
Froude
in
(S8-1) with
pipes
)1/2 ) deposited
beds
constant
transport
of
in
parameter (N/s);
Ackers'
May's
equation
mobility
parameter
sediment
transport
at
height
H
Dunes'
J
Ackers'
parameter
k
Linear
roughness
ko
Clear-water
ka
Overall
ksb
Bed
representing
height sand
equivalent sand
equivalent
equivalent
sand
roughness
roughness
roughness Xi x
with
of
with
rigid sediment
sediment
bed
K
Ackers'
L
Dunes'
m
Empirical
n
Manning
roughness
Ackers'
equation
parameter
incipient
representing
motion
length in
parameter
na
Clear-water
ns
Overall
Manning
P
Wetted
parameter
q
Unit
flow
Q
Flow
discharge
Qq
Absolute
Manning
Overall
Rb
Bed
Re
Flow
s
Standard
So
Bed
SC
Slope
Ss
Specific
T
Temperature
u
Particle
coefficient
with
(= Q/B)
discharge
discharge
(N. m1,5 /
hydraulic
of
flow
the
of
S2.5 ) (=
radius
A/P)
radius
Reynolds
(=
number
4VR/y)
deviation
slope (=
parameter gravity
So/ (SS
of
1) )
-
(=
sediment
ps/p
)
velocity
Shear
velocity
V
Mean velocity
of
flow
VV
Mean
of
flow
Wb
Sediment
We
Effective
WS
Width
of
sediment
ya
Depth
of
uniform
YS
Thickness
velocity bed
in
width
for
incipient
motion
pipes
width
of
spread
flow
sediment
bed.
XX
in
clean
in
parameter
coefficient
roughness
hydraulic
R
empirical
roughness
rate
equation
coefficient,
sediment
QSz Transport
Ackers'
pipes
rigid
bed
sediment
(=
depth
flow
Y
Overall
C
Friction
angle
ß
Velocity
distribution
Ys
Specific
weight
Ic
Clear
Is
Overall
"sb
Bed
1g
Grain
roughness
11
May's
transport
8
May's
related
6b
Bed mobility
V
Kinematic
P
Density
of
water
Ps
Density
of
sediment
To
Mean
Tb
Bed
between
factor with
sediment
(Pipes
parameter
(= (=p
fluid
pgRS) g%S )
(=
parameter intensity
or
May's
transport
parameter
velocity
deposited
factor
of
viscosity
stress
with
= (11fib)
number
stress
sediment
with
Shear
Settling
sediment
factor
transition
shear
and
sediment
of
factor
friction
channel
coefficient
friction
Transport
the
friction
water
shear
yo + ys )
flow
of
CvVR/ (gd3 (S$ 1) )112) parameter (Clean
particle
xxi
(_ pipes)
(Se
1)d/SR))
beds)
1
CHAPTER
INTRODUCTION
Background
1.1
The
in
studies
'Several
in
sediments
Besides
and
guide
practice
designed
velocity any
al
1991,
limiting
in
several the
supply
sediment,
and
studies
single
sediment the is
that
the
aim
point
out
1990,
is
most
of
resulting
1
blockage, design
of
of
(Mayerle the small to
enough
single sewers prevent
deposition
size
et
highlight
studies
and
important
equations
free
sewers
while for
not
the
either
works
that
have
sewers
the
sediment
Another
might
criterion,
These
sewers.
sewers
review
results it
size.
A
recent
concentration,
the
to
presence
in
keeping
of
influencing
sewer
the
critical
500mm),
factors
important
Verbanck
example,
that
conservative
larger
1991,
few.
a
shows
1978)
than
smaller
pollution
sediment
However,
Ackers
deposition
sediment
a
with
gives
criterion
(diameters
these
stress
1982,
May
1987)
on
of
subject
of
relate
for
name
deposition.
sediment
of
to
mainly shear
or
of
problems
(CIRIA,
the
concentrations.
presence
flooding
al
to
pollutant
other
and
et
attempted
the
several
surcharging,
as
to
sewers
pollution,
produce
been
have
been fear
the
to (Ashley
studies
1990)
al
et
has
sewers
due
years
recent
watercourses. Larson
sediments
of
movement
in
such
density
finding
obtained
of from
give.
larger
significantly
the
to
those
sewer
tested.
originally (mostly
pipes
small
to
extrapolated
sizes
This
result
) used
150mm dia.
in
experiments.
(1984)
Henderson
in
roughness the
that
drew
but
the
and
ageing
due
roughness
their
transporting
et
hydraulic
roughness
the
importance
The
(1978) would steeper However, the
where lead
to
sewers
while
used
sewers.
in
Laplace
stationary this
of he
finding
suggested slopes
as
produced
limited transporting
data
al
sediment
milder
slopes
et
was that
by
the
the
Recent
works
1992)
conceptually
sediment
2
occur
of
sewers -
on the
(Ashley
depth large
pipes.
studies
raised
"limited
sewers
deposits.
to
(for
permanently-
found
also
deposits
hinders of
of
in
loss
a
smooth
conducting
for
to
in
studies
in
presence
required
available capacity
a
increase
earlier
conducted
the
reported
1992,
Verbanck
mostly
lead
the
sliming,
The
might
However,
were
in
sediments
possible
factors
show by
only
sections,
deposits.
sewer
studies
not
the
of
of
His
influenced
sediment
these
(1964)
al
for
to
1988)
deposited
1992,
of
capacities.
Mayerle
Ackers
is
jointing
the
also
importance
the
performance.
sewer
roughness
presence
sewer
example,
the
hydraulic
sewer
to
attention to
relation
materials
sewer
of
than
due
been
have
might
when
predictions
widely-differing
free
et
al
that
it
is
in
sewers.
by Ackers deposits" instead criterion.
the
quantitative
studies
with
stationary
sediment
of
1.2
Scope
The present
the
that
influencing
the
to
gain
in
the
sewer
transporting
The of Ltd.,
texture size,
sewer sewer
c)
sediment
by
of
sewers
or
wall
the
of
the
in
All flow
smooth
research
and were
sediment
transport
sediment
transport the
supplementing factors
the
on
1990).
load
improved
achieved
factor
lack
influencing
of the
namely,
roughness,
and
deposits
were
experiments University
the
is
aims
on
provide
studies
capacity
a) b)
to
and This
in
data
understanding
sewers
relationships.
The
is
uniform
bed
as
it
another
part-full
transported
boundaries.
improved
an
process
loose
and
rigid
under
storm
though
even
(Alvarez
capacity
conducted
separate
be
would
transporting
stormwater,
for used
were
itself
sediments
carrying
mainly
sediments
sewer
with
conditions
sewers
applicable
cohesion
were
experiments
rough
are
non-cohesive
acknowledged
for
intended
were
results
Only
sewers.
Study
studies
hence
and
Present
of
of
carried
out
Newcastle
the
at
Hydraulic
Tyne
upon
and
Laboratories
Hydraulic
Research
Wallingford.
1.3
Outline
This
thesis
of
The
consists
Following
the
Sediments
in
Thesis
of
introductory, Sewers"
gives
seven
chapters
chapter, a review
3
and Chapter
on the
three 2 on
behaviour
appendices. "Nature
the of
sediments
of
in
incorporating
sewers
sewers
and
the design
current
3 entitled
Chapter
experimental
and
studies
4 covers
Chapter describes the
the
the
for
sediment
the
It
the
highlighting
details
of
of
and in
adopted
the
test
pipes, It
characteristics.
also
flow
uniform
and
experiments.
Analyses"
factors
sewers
Procedures"
procedures
transport
load
data
the
presents
bed
the
in
boundaries.
and
establishment
presents
the
loose
and
sediment
"Preliminary also
the
real
presents
transport
Apparatus
with and
Literature"
and
apparatus
for
roughness. of
experimental
5 on the
rigid
in
works
practice.
on sediment
"Experimental
the
method
procedures
Chapter
both
techniques,
measurement gives
for
in
Relevant
of
field
of
used
works
investigation,
present
results
criteria
"Review
the
a summary of relevant
recent
results
influencing
on pipe the
with
the
aim
self-cleansing
velocity.
6 consists
Chapter where
analyses
each
the
established
transport analyses. performance
analysis
transport
established
Design the
examples newly
in
loose starts
the
using
the
with
later
are derived
then help
of
Data"
sediment
transport
are
described.
comparisons
among
the
data.
present
considered multiple
presented
transport
4
the
with
are
Transport
boundaries
relationships
relationships
models
of
and
Sediment
of
obtained
rigid
the
functional
"Analyses
data
the
both
boundary,
For
Several
of for
experiments
the
of
to
equations
and
new
regression compare
the
with
the
equations
established
and
also
to
assess
the
current
design
practice.
7 entitled
Finally
Chapter
Further
Research"
present
study
works
in
light
summarises
and suggests of
the
present
"Conclusions the
and Recommendations
conclusions
several study.
from
obtained
recommendations
for
for the
further
2
CHAPTER
NATURE
2.1
OF
SEDIMENTS
IN
SEWERS
Background
Due
to
in
variation in
some extent hence
sewers transport
flows
sewerage
The
systems.
involves
a
cycle
deposition
and
have
sediments
of
though
been
always
movement
of
processes not
present
to
sediments
in
namely
erosion,
in
strictly
the
order
mentioned.
(1987)
CIRIA the
conducted
presence
found
of
operation, were
surfacing
materials
be
given
affected
use,
time
and
mainly year
by and
Ashley-Crabtree(1992) studies
(Ashley
spatial
variations
types
but
inputs also
et
to
further
sewers
sources
also
(1992).
Xanthopoulos-Augustin
similar
of
yields
and
(1992) 6
of road
surrounding
ground
discovered
were
to land
type,
sewer
in
works there
origins not
only
inlets.
sewer
results
sources
period.
that
may differ
adjacent
studies
give
indicate
commonly premature
important
location,
reported
most
operations,
ingress
sediment
The
to
related
flooding,
gritting
dry
the
between
winter
preceding
in
problems
UK.
The
geographical
1992)
the
quality.
The
al
on
surcharging,
roadworks,
work.
of
sediment'
as
in
sewers
and water
construction
studies
blockage,
were
sediments
and
in
sediments
problems
overflow
extensive
to
those carried
the
are of
UK.
considerable
sediments
between Other of out
New
where
catchment recent
Ashley samplings
et
al of
types
sediment with
combined
that
the
and
of
there
are
several
for
sewers,
instance
studies
recent
(1987)
CIRIA's
Recent
have
sewers
2.2
with
stationary
Characteristics
CIRIA
(1987)
quantity found
of to
those
gave
samplings
between deposited
in
2.5mm.
the
that
inside In
the
general,
ones
obtained
1992,
Laplace
the
following
and
Quantity
sediment
from
Details (See
section
et
al
concentrations
deposits.
sediment
these
of
Section
2.2.2).
Sediments
of
comprehensive
in
eleven
and
review sewerage
locations
where
the
invert
generally
storm
sewers
The
sediment
CIRIA
of
in
cities
9.0mm.
in
the
sewers
(1982)
May and
reported
concentration
7
systems the
is
the was
which
were were to
herein.
reported
the
studied
and
relating
1987)
with
source
samplings
(1987)
UK (CIRIA
well-graded
the
on
the
findings
the
made
are
in
the
on
of
at
0.1
the
Verbanck
quantify
present
be dependent
sediments
1992,
al to
a
sediments
samplings
found
partition. to
results
main
Studies
A summary
made.
about
in
given
Earlier
the
et
attempted
2.2.1
The
(Ashley
also
are
studies
similar
the
deposition
flow
from
show
studies.
studies
1992)
downstream
produce
for
sections
results
(1992)
Bachoc
areas
that
and
runoff.
street
vulnerable
The
site-specific
were
was the
catchment
systems.
sewerage
separate sizes
solids
different
at
concentrations
sediment
source
in
and
range the
average found
that
showed
(=dso)
sediments d30 size to
be
of
2oppm
by volume 1.83m
dia.
in
with
gravel
in the
0.34mm
conducted
samplings
sediments
in
of
range
the
particles
et
Mittelstadt
found 7 to
varied
from
These
studies the
the
110
sewers of
by
a mean
2.1)
mainly
of
depths sand
sewers
(1983)
Shultz and
obtained
(1984)
studied
average
specific sediments.
volumetric
of
that coarse
sediment the
where 50
about
the
values
ppm.
sediments low
with
and
sediments
coarse
researchers
Table
are
Broecker
compiled
of
of
Germany
implying
2.45
about
size
the
depths
combined
and
reported
and
ppm with
inverts
2.0mm.
to
previous
(see
in
cities
(1979)
suggest
sewer
0.06
mean
(1983)
Macke
several
al
concentrations
in
found
of
combined
from
and
in
in
deposition gravity
the
12mm.
sediments
the
average up
to
of
2.94mm.
and
300mm made
0.54mm
40mm in
the
the
gave
samples
Slovakia
about
measured
and
25mm to
between
of
(1964)
sewers
of
size
deposit
of
al
combined
obtained
Bratislava,
between
et
range
median
(1984)
Urcikan in
sewer.
deposit
depth
average Ackers
deposits
sediment of
the
with
present volumetric
concentration.
2.2.2
,
Recent
Studies
Following
CIRIA
occurence
of
polluting
and
deposits.
(1987)
sediment
studies, deposits
operational
Herein
only
several have
aspect the
new investigations
been
going
resulting
results
8
relating
on to from
on the
quantify
these to
the
sediment
operational
aspects,
linked
maintain
the
to
the
designed
2.1
TABLE AUTHOR
cleaning
hydraulic
operation
capacity,
0.10
of
the
be
discussed.
IN
VOLUMETRIC CONCENTRATION (ppm)
9.00
2.50
MACKE (1983)
0.06
URCIKAN (1984)
0.34
20
-
2.00
-
2.94 2.45
BROECKER (1984) MITTELSDADT (1979)
7-
(1992)
Verbanck June
1986
in
4.0m
dia.
and
5.4km
Fig.
2.1
of
development
of
deposit Fig. time.
The
the
also Analysis
effects shown
further of
in
shown
2.2)
observed
in
Fig.
was
2.1
the
2.3
generally
illustrates
level
a stable taken
along 9
the
volume trunk.
be
without
a
bed
load
on
the
'mean
very of
a
gradual
period
invert
of
indicates
to
operations
the
of
The
cleaning were
The
main
deposits. during
the
the the
of
of
(Verbanck
time
of
Fig.
deposits
of
samples
in
length
total
sewer
length
time
with
sediment
(Fig.
total
since
0.0004.
of
reproducible
the
trunk
slope
the
on
110
profiles
combined
average
evolution
events
stationary
as
an
very
stationary
operations
level 2.3
be
for
of
main
profile
calculated
development
process.
with
to
shows
study
closer
cleaning
long
found
deposits,
the A
been
accumulation
(Belgium)
accumulation
has
1990).
sediment
obtained
a Brussels
longitudinal sewer
to
sewers
SEWERS
SPECIFIC GRAVITY
PARTICLE SIZE (mm)
MAY (1982)
,. r
will
SEDIMENT CHARACTERISTICS (See CIRIA 1987)
(1987)
CIRIA
costly
limited.
deposits of
the
over sewer
1200 Storm of 14 Sept. loge (. xtnn. ly violent)
23/081
1000
00/01 /87 To
I
24/00 00/09 OT/04 E3 Q
QQ
O CL
800
O0 13
QQQ
Cleaning out
Q 10/02/88
Q
26/10/88
w 0 U. 0 W
600
1 ,,/86 ea Cl
0
14-16
nn
6apt.
1
rain 1988
0 20/00/88
Anti
ývv
Dec-88
Jun-86 TIME (months)
FIG. 2.1 Build-up of sediment on the invert of Brussels main trunk sewer (After Verbanck 1992)
40
c 0 0 12
Co
E U
ob S. 01
0
CL 0
v 0 m > Jm
to
1.7
1.8
1.9 2 2.1 Kilometres
2.2 f2.3
2.4
1 2 3 4
11-Jun-86 03-Jul-86 11-Sep-86 16-Oct-86
5 6
n9-nH--RA 09-Jan-87
Input 2
e.
4:
,ý`
FIG. 2.2 Detailed view of gradual sediment build-up (After Verbanck 1992)
ýý
ý.
ý,ý
10
that
showed
the
(=dso)
from
ranging
July
Since
sediments
1988
deposits
in
(France)
for
a
wide)
with
indicates
the
which
profiles of
time.
with
invert between load
process
load
et
was
3.0mm,
al
(1992)
sediment
of
deposits level. gave
a size
concentrations
(Ashley-Crabtree
for
trend
of
particle
of
sediments
in
the
size
of
the
bed
that of
some
formation
sediments
concluded
stationary
transported
as
of
),
0.1
found shows
show of
the
to
0.5
to
vary
sediments
11
an interceptor The
175m
and
measurements
yet
Samplings
in
1986.
since
The
not
1992)
level
the
of
the
formation
mm dia.
0.00069.
were
the
an equilibrium
deposition
(UK)
(1500
range
1.80m
succession
the
sediment
Dundee
do
and
asymptotic
average al
made
25ppm.
studied
circular
equilibrium
et
were
shows
manner of
an
Laplace
be
to
at
slope
average
gave
concentration
found
approximately
the
sampling
responsible
was
sewer
combined
load
and
which
Corresponding
Ashley
invert
sewer,
0.3mm
beds. bed
the
of
a
of
Marseille
high
reaching
represents
the
on
The
of
in
2.4
Fig.
deposits
the
formation
the
(2.75m
studied.
2.5
Based
sands
observations
sewer
an indication
gives
well-graded
sewer
The
0.001.
of
of Fig.
deposits.
the
trunk
years.
period
possibility
of
followed
egg-shape
slope
the
over
two
the
an average
(1992)
combined
of of
up
made
mm.
al
man-entry
a 460m section
level
et
a period
deposits
0.5
to
Laplace
along
of
0.2
were
a
of
tendency sediments
mm. up
The to
found
long
with
an
the
level
of
to
reach
an
on
the
volumetric 20ppm. in
is
sewer
sewer bed
Fig. sewers
2.6 from
25
. "'0
20 4
E U
"l.
15
oa
Ctboa o° q3 o
0 m V
10
C
a
13
0
o
0
0
0 6
rain event leading to scouring rain event leading to deposition "
I,
Jun-86 FIG. 2.3 deposition
1988
1987
Effect (After
measurement during cleaning
1989
of cleaning operation 1992) Verbanck
1990
Jun-91
on sediment
120 110 100 90 BO 70 0 60 50 40 w
30 20 10 0
C
10 NUMBER
20 OF
MONTHS-AFTER
COMPLETE
30 DREDGING
FIG. 2.4 Long-term trend of volume deposited (After Laplace et al 1992)
12
5.0 Intake
5.!
S. 2 W
S. 0
4.8
4.6
4.4 100
0
[m]
ABSCISSE
Longitudinal FIG. 2.5 (After Laplace et al
profile 1992)
400
300
200
of
sediment
depth
DUNDEE INTERCEPTOR DUNDEE
BED-LOAD
(DWF INTERCEPTOR)
SEDIMENT
100 90 80 -ý
70
rt
60 (d
U Si d
50 40
30
20 10 0
10
100
1000
10000
micron
FIG. 2.6. Typical partical (After Ashley et al 1992)
13
sizes found in sewer inverts
recent
(Ashley
studies
Ristenpart
range
al
1992).
from
recent
et
The results of
sediment
be concluded
equilibrium
level
Classification
Based
on studies
which
showed into
insight
location
presence
the
nature
a
of
it
time
the
al,
on the
agreement of
is
et
sewers.
It
to
an
possible
reach
Sewers
and
(1988)
Crabtree
deposits
sediment
combined
sewer based
category sewerage
Laplace
deposits.
(1987),
of
five-fold
within
over
invert
the
Sediments
by CIRIA
the
a
suggested
in
sediment
of
1992,
Verbanck
show a general
found that
of
1992,
al
studies
sizes
can also
2.3
et
system,
to
gain
sites a greater
deposits.
sediment on
and
revisited
visual
He
appearance,
physical
and
chemical
analysis:
Classes
:-ACD-
coarse Class mineral mobile organic
E-
deposits
B-
Among
these,
invert mentioned of
the
of
Class
sewers. in
Section
granular material A deposits concreted cements fine grained - usually wall slimes
found
A represents This 2.2
is
in
in
suggesting
classification.
t
14
greases
and A
overlying
tanks
typical general
by
sediments agreement
the
universal
with
found the
in
the
results
applicability
Following
their
attempted
to
cumulative
contributing
distinguishable results
Dundee
are
sewers
Modes
the
and
2)
or
continuous
transport
mode)
of
sediments
is
possible at
organic
the
A)
while
and
size.
The
deposits
are
In
the
trunk
interceptor
the
(Class
particles
on the
and
the
also
sediments
1)
in
transport
sediments
mode)
or
physical level
of
move
time.
15
will
roll
and/
and chemical turbulence. both
as
sewers with
deposits,
sediment
The
depending
same
C).
sediments :
loose
over
the
of
categories
dunes.
if
size
G).
Transport
(suspended-load
suspension
load
two
sewer
(Class
finer
or
sediment
collector
(Class
movement
into
and
head of networks flows from
relative
relative
coarser
with
Sediment
of
the
material
are
slope
gradient
increasing
of
the
that
organic
deposited
general
classified
load
by
show
deposits
the
sewers,
In
are
migrating
mainly
2.4
categories
(1992)
al
disposals
to
collectors interceptors flat large,
-
et
diameter,
on
local at small, convey - steeper,
principally
at
Ashley
area:
catchment
Interceptors
these
general
based
sewers
Collectors Trunks
:-
(UK),
Dundee
at
classify
Classes
In
work
clean
invert dunes
separated
either or
be
could
move
in
(bed-
saltate characteristics Total-load
suspended
load
mode and
bed
Based on the
classifications
(1955)
al
May et
likely
are
(1989)
runoff
(1992)
move
in
on
sediment
Sewer
in
sewers
the
He
sand
Colebrook-White
0.4mm
than
that
finer
fraction
larger
0.125
mm will
than
larger
than
of storm
0.4mm
will
move
of for
can
be
concluded
of
transport
mode
for
that for
sediments
non-cohesive
load.
Roughness
out
studies
obtain
al
hydraulic
a realistic his
combined et
on
of
previous
data
with
to
come
up
1964)
roughness,
appraisal
own
k-values,
in
roughness
with
existing work
suggested from
calculated
the
equation.
2.2 gives
condition
it
UK to
Ackers
of
equivalent
account
and Spells
coarser
suggested
sediments
carried
capacity.
(mainly
'k
(1955)
a classification
sediments
the
mm,
(1984)
Henderson
Table
that
be bed
will
Hydraulic
sewer
load.
sizes
0.4
than
particles
used
bed
while
sediments
proposed they
found
al
load.
where as
et
load.
larger
2.5"
move
suspension
bed
Based
will
(1992)
Verbanck
as
particles
0.6mm
than
bed
as
Xanthopoulos-Augustine water
that
suggest
be moving
to
by Newitt
k-values
pipefull sewers.
any
These
misalignment
for
k-values the
of
16
pipe
sewers
should sections
be and
for
the given
modified the
suggested
to
PIPE-FULL k-VALUES FOR PIPE SEWERS TABLE 2.2 (AFTER HENDERSON, 1984)
SUGGESTED k, VALUE (mm)
TYPICALCONDITION Virtually as new condition. Light coating of slime (55
k, DUE TO JOINT ECCENTRICITY (mm)
0.15 0.30 0.60 1.5 3.0 6.0 15.0
17
(Henderson
values
1984) and
slime
material, would
it
2.2
From Table alignment, the
pipefull
k-values
The
Water
Authorities
for
use:
0.6mm
2.6
Current
Sewers
storm
is
deposits
(1987) design
shear
criteria
are
be expected
0.3
1989)
1.5mm
to
be
3.0
to
mm.
in
its
k-values
the
for
good
deposits,
suggested
combined
to
sewers.
the
self-cleansing. to
expected intermittent
during
continuously of
flows
receding
conditions,
it
picked-up
by
high
flush
the
available
is
All
move nature
these
thoroughly
reviewed in
criteria
self-cleansing or
WAA,
with
dry
or
expected hence
flows,
the
weather that
hindering
the any
deposition.
long-term
and
sewers sediment
no
and
designed sewers
be
would
k-values
Criteria
Under
conditions.
for
(WAA) (
pipe
deposits.
between
range
sewers
Due to
to
the
Adoption
water
entering
deposition
CIRIA
for
deposition.
without
and
Association
generally
sediments
invert
in
are
Design
are
that
Besides
different
sediment
concluded of
sliming
Sewers
publication,
be
2.3.
Table joints,
of with
sewers
can
minimum
in
given
misalignment
for
be obtained
are
the
criterion Tables
stress. given
in
CIRIA
UK and
is based 2.4
elsewhere.
either and
(1987).
18
codes
2.5
In
of
practice
general.
the
on minimum mean velocity reproduce
some
of
the
2.4
TABLE
REFERENCE SOURCE AMERICAN
CONSTANT VELOCITY (See CIRIA 1987)
COUNTRY
SEWER TYPE
MINIMUM VELOCITY
USA
FOUL
0.6
SOCIETY OF CIVIL ENGINEERS (1970) BRITISH
PIPE CONDITIONS FULL/HALF-
FULL
UK
STANDARD (1987) ESCRITT
CRITERIA
STORM
0.9
STORM
0.75
FULL
COMBINED
1.0
FULL
0.76
FULL
1.5
FULL
UK
FULL/HALFFULL
(1979) BIELECKI (1982)
GERMANY
TABLE
REFERENCE SOURCE
2.5
CONSTANT SHEAR STRESS (See CIRIA 1987)
COUNTRY
SEWER TYPE
CRITERIA
MINIMUM SHEAR STRESS
PIPE CONDITIONS
(N/m2) MAGUIRE
UK
6.2
FULL/HALF-
RULE YAO (1974)
FULL USA
LYSNE (1969)
NORWAY
ASVISNINGAR
SWEDEN
STORM
3.0
-
4.0
FOUL
1.0
-
2.0
2.0
-
3.0
1.5
(1976)
19
Using
the
Arora
et
transport al
velocity 1985) design
1984)
based
criterion and
Fig.
practice
(D < 500mm)
and
(Novak-Nalluri
relationships on
was 2.8
recent
overdesigns underdesigns
experimental
appraised
(Ackers,
as 1984).
the the
1975,
slope slope
20
shown
Fig.
In
general,
for
small
for
the
works, in
larger
May
the
pipe
minimum (Nalluri,
2.7
pipe
1982,
present diameters
diameters.
C,, = l00ppm d=0.4mm n=0.01 Half-full pipe
1 10
41
ora
t $1 (1984
a,
J
)
Novak_Nalluri (1975)
0
10
'ýof
o0
Vý
h0
b00 00 00 O ý q0ý
10ý
100 FIG. 2.7 Appraisal (1985) Nalluri
100r -m
I
Q ! /s
design
of present
due to
practice
1000
100
10
102
10000
100
c 0 N 7
0 IC
0
Iu CL
In C W V (7
b 111.1
0.5
r
N .
t11t111111......
1
10
FIG. 2.8 Appraisal Ackers (1984)
Discharge
of present
100 for halt-full
design
..
1000 pipe. Its
pfactice
'
0.1 000
due to
21 a
CHAPTER 3
3.1
Background
Majority deal be
LITERATURE
OF RELEVANT
REVIEW
the
of
in
found
(1984),
on
works
textbooks
standard
Garde-Ranga
Van
of
information
(1989)
Rijn
could
(1975),
Vanoni
as
such
(1985),
Raju
deal
transport
sediment
and
motion A good
channels.
alluvial
with
incipient
Graf
Raudkivi
and
(1990).
There of
however
are
rate
supply the
sewers
itself
of the
Secondly,
the
whether sediment
deposits.
also sewers.
of
have
drawbacks The
transportations
sediment are
effectively
sewers
slurries direct
concentrations higher
than
22
clean
in
made
in pipelines application and those
in
from
the 2.1.
Section depending
varies
or
derived while
determined
of
the
much
is
roughness is
is
unlimited
discussed
of in
is
Firstly,
channel
alluvial
in
transport
mentioning.
as
sewers
on transportation
an
Two
sewers.
sediment
worthwhile
in
application
in
system
sewerage
invert
of
sediments
of
effective
the
Studies
and
rate
supply
catchment
are
direct
the
conditions
mechanism
sediments
of
channel the
the
and sewers
channels
alluvial
from
in
to
the
to
models
differences
important
the
several
boundary
loose
limitations
up
of
on loose
(Vanoni to
velocities attainable
1975)
problems in in
slurry sewers.
in
The
the
(1955) both
transport
this
the
studies
UK by
deposits
transport
over
Kleijwegt
1992).
identify
be
those
of
work
was
and
sediment deposition) reported
on
to
following areas
these
with
studied
et new
gain
a
sections which
are
not
1989,
al
of
to
better
studies
of
Perrusquia
1991,
still
remain
understanding
summarize
existing
fully
covered
yet
permanent
the
there
works,
(CIRIA
data
presence
in
mainly
Field
leading
(May
beds
resumed
(1975).
the
inverts,
their
Even
The
problems.
limit
sewers
May
and
revealed
sewers on
in
boundary
rigid
deposited
to
need
further
no
(1972)
used
sediment
areas
on
Novak-Nalluri
from
1987)
However,
(1953)
covering the
Under
1970.
until
subject
Transport
beds.
(at
sewers
USA.
Ambrose
experiments
boundary
rigid
(1953),
Craven
conducted
with
loose
over
(1956),
University,
Iowa
at
in
transport
sediment
researchers
Laursen
of
guidance
Valentine
and
by the
presented
were
on
studies
reported
earliest
the
of works by
and
previous
studies.
3.2
Incipient
Studies in
of
Motion
incipient
Raudkivi"1990)
rate
such
1987). observations
show The as the The
that
there
category
works
by Shields
particle
beginning
Graf
first
second of
or
(e. g.
channels
alluvial
threshold.
motion
1984,
are
two
is
based
possible on
constitutes on
23
the
of
sediments
Lavelle-Mofjeld
and Kramer
definition motion
movement
bed.
definitions
a minimum (see
1987, of
transport
Lavelle-Mofjeld of
the
visual
by
Work
(see
Shields for
standard
defined
Shields
the
interpolation
and
is
'c
where
S. is
the
the
sediment,
threshold
is
shear shear
critical
shear
viscosity
of of
dimensionless
given
in
Table
and
SHIELDS'
D6r 4
O o
o--ý C 4-4
o1 ý. N +J a c. co UG ýn 3 ý4-e 92 Co
F+ cý
CO c
UZ
Co U2 M C.)
a ",
g
N Id "U
Cý
Lz. U
. ýý . _,
ý
-v
.a
0ppO
ýu
th`%VIP ftsý' 0
36
VN
V-1.77
ýß
(d)
C,
ý A;
(3.15)
dl1 (S; 1) s
Macke
(1982)
using
three
smooth
full
part
conducted
and
both
moving model
(192mm,
pipes
used
sands
fitted
it
analysis
for
following
dimensional
the
with
to case
a theoretical regression in
resulting
Region
in
I
Fig.
is
Q.
the
sediment
fall
sediment
densities
transport
for
the
due
to
size
in
of
this
bed
load
transport
load of
to
(3.16)
(Region
II).
I)
37
(1982)
and
Nm"S/s2. S.
However,
relationship II
in
as functions data 1972)
validity and
water
the
sediment
Region
Robinson-Graf
w is
of
a specific
experimental
May
range
obtain
the
the
are
4x10-3
curves
(Region
p. The
(see
individual
N. m1.3/s2'3,
10-6 to
transport
established
transport
p and
respectively. was
1953,
in
rate
and,
By using
Ambrose (1982)
kg/m3
attempt
region.
(eg.
m/s,
studied
not
presence
Macke
suspended load
", Q,
did
case
research 3.8,
in
rates,
the
in
velocity
(1982)
Macke
transport
sediment
the
3.8):
Qý = Q(P. - P)8(1s - 1.64 x 10-4 i
where
0.37mm
and
linear
load
(see
equation
by
data
suspended
of
) flowing
dso) 0.16mm
He derived
experimental
deposition
of
445mm dia.
and (=
of
loads.
and bed
as suspended
and
290mm,
sizes
limit
the
at
experiments
individual re-wrote
as of
Fig. of
from shown Eqn. curves Eqn.
3.8)
sediment previous in
Fig.
3.16
for
for 3.16
bed as:
i : iI
:ý:..
. l: l . ll
Mill
114-1* ti::
i:.
}..
...
iii
7 4..
""i
(P , P) g Cau Q ý=Q . . . )i'Iý. . ' 1_ - .. ý,, nj t : IFl
10
iý!
.: ý""t'
__
.s
I
:Ail!
I",
;.,.
.
:4:...
O.
t.
'..::
ý1
( !i i
Alu .
nW
F l ow con ditio n s with sedimentation
j
'i1,
hill
.;
iý
:
i
1
; i:
ii
t 3_.
II
,,.
j ii
j
tt
'i
'.
I I:.
.. ii''
I
l..
...
t
It
r?
1'ýT: It.
Iii
p
1C
96 .
--1.64 x 10-4 s2
T! I
1( 'ý, i" i
; JI
...;
_yýý
},
i
I. ýt . ý-
* =::
ü f'ü ?
.,: "I i:
:. f
I
l:
i
Iýt.
lii.:
ti
.
t; 1a
tlll
c
'i. '?.`?ic;
}li :::.
-I
l
-tl: oi
iti f Zül
iii
.
I.
ýý.
c
_
y'
ri i ut:L, ': L.
-2
.1
ZL'
ýS " i
'
z: -" . ^ .«
r: -,:
11
fi 1-
_
ýý r-Iý_Q_
-
.1 lY:
Ii., cý":
I;!;
_=
c=
=v_
'
"1
ý.. i
ýi : : -'ate
r_-
..; ý:.
. ---
''...,
ltl mt. .
;-1
:i
_ mß-3
.'.,
.
r.
1-
, =:.".s'
1º .:
0ý
REGION II
L- "!
..
'-
`
pit
t':
}i! i 5'_3 i
t"fl
by Macke (1982)
IT
} lii `ij: ":;;'.ý#, "I .
il 't
_
" CRAVEN(1953) V DURAHD(1953)
' -'
o EINSTEIN at al. (1972) (1961 ) - FOHRBOTER
=-
FOHRBOTER at al. (197S) s FDHRBDTER at al. (1981) (1976) f KtPAIcASS31415
Untersuchungenan IEICHTWEISS-INSTIT. T
o-
" ROBINSON,GRAF (1972
2,
*SAUERMANN(1978)
'i~'"'+i:: t[ 7ý I q:f : " .
10 ae-
.
f::: ýi
legende o Al82OSE(1953)
=`
REGION It
.. tt" 1 "
171 .
ij gj?: i Tý'i, iii " -,
Region studied
-`ý-
tl: "'
ý
T
`r"~
11 " ý1
"1:;.;
"
iii ; -_
---
" Elcene Unu"sutnun-en -_
Abb
7 2 . .
--
Feststolftransportrate von der
a'
QS
Wandscnu b s; annun9
(Auswertung btasnnter
:a'
{
:i " i .
10x6 10-1
a
ßi; 1
.I:ii
:ý+
_
1"
to
AohYnQs ptit
t
Untersuenungen)
ýi:i:
t: .i:
; i. .. t 0
a"
ii
+if,
06
23"ss;.
sjo1
33a
Zaai02
i3i1
1 4149-1
03
FIG.. 3.8 Suspended load model at limit of deposition flow in pipes (After Macke 1982) for part-full
38
V=1.98
it
Again, SI
be noted
should should
units
fall
sediment following
May
is
(1982)
g in
m2/s,
(1982)
developed
0.64mm
forces
", on
7.9mm
to
at
theoretical
model
experimental
acting
the
by
from
the
range
of
(3.17x)
4.7
Eqn.
< Cv (ppm)
the
SB = 2.65.
39
bed
following
3R
for
May
particles the
and
fitted
equation:
(3.18)
velocity
< V(m/s)
is
which
V4 1-V
experimental 0.45
load.
simplified
analysis
motion The
< 2100
sizes
model
He
d ob v2 R g(s-1)D
3.4.
Sediment
sediment
dimensional in
158mm
transport
incipient
critical
as
individual
resulting
Ds
part-full.
deposition.
of
77mm and
using
bed-load
utilising
data
(1975)
Novak-Nalluri's the
the
calculated
transported
and
on
limit
the
Cý=0.0205
Vc is
and
a theoretical
transported
where
that
mm.
deposition
of full
flowing
pipes
d in
and
m/s2
limit
the
studied
ranged
to
be
should
m/s,
suggests
[0.11607 + 0.074405 d] a 10'3
from
it
also
hence
and
ý9v2+ 10-9 d2 g (S, 3v (0.03869 + -0.0248d)]"R -1)
in
-smooth
based:
eº in
dimensional
equation:
v
dia.
(1982)
May
used.
velocity,
ý_
where
be
is
3.17
Eqn.
that
(3.17 )
((So-1) A Cy )u
1003
given data
by
covered < 1.2
and
May
(1989)
al
et
larger
using
pipe
as bed
transported 1982)
were
depth
(yo/D)
flows,
extended
300mm
a load.
to
and
reduce
the
in
scatter
sand
pipes
(May flow
proportional for
data
the
0.72mm
smaller
of
effect
a
part-full
yielding:
y
C, = 0.0211
Analyses
provided
The
covered
the
range
60 (d =2. Omm)
FOR ACKERS'
EQN.
3.29
TRANSITIONAL AND FINE SEDIMENTS 1< Dgr j 60 (d = 0.02 2.00mm) -
n=0.0
n=1.00
Aar = 0.17
Agr = 0.14
m=1.78
m=1.67
C=0.025
log
C=
-
0.56
log
+ 0.23/
Dgr Dgr
+ 6.83/Dgr
+ 2.79109
-3.46
47
Dgr - 0.98(1og
Dgr) 2
(1987)
Mat
Suki
in
smooth
159mm,
8.00mm)
using the
with pipe
sands
whole
k0,
roughnesses,
from
= 249mm),
3.32mm
= 155mm).
Mat
effects
the
single
model
limit
of
Using to
linear
multiple data
experimental
(D = 159mm)
1.61mm
(D
(D = 159mm)
and
8.84mm
(D
high
values bed-load
on
smooth
forces
and
regression
g(Sý 1)d
for
smooth
2.86 c
pipes
the
transport acting
rough
analysis
on
was
fit
the
to
-1A
)) °_ D.
l0 4.80. k.
and,
48
2.01D(d+ký+ °" dk
a
pipes
yielded:
(d+;k)O"22 0
ko to
of
[1o43.13(1+... V
sand
were
based for
applicable
using
equivalent
A theoretical
deposition,
For
equation
these
atttributed
-
roughened
1.3mm ,
resulting
4.73mm
2.65.
of
roughnesses
249mm)
Colebrook-White
misalignments.
particle,
derived.
The
were
1.30mm
=
artificially
uniform
creating
(D = 162mm),
(d50
average
were
pipes
(155mm,
pipes
experiments
size
the
on
deposition
of
rough The
sediment
(D = 162mm and
the
Suki
joint
of at
model
the
155mm).
=
full.
gravity
0.83mm
(D
2.7mm
of
perimeter
diameter
of
and
specific
) and
) flowing
range
conditions,
the
around
a
limit
the
at
253mm dia.
and
249mm dia.
162mm and out
experiments
(164mm
pipes
carried
rough
conducted
(3.32)
-lA
the
pipe
smooth
is
k,,
roughness,
sand
equivalent indeterminate
taken
as
0.3mm
instead
of
in
sand
equivalent 0.0mm.
Using lead
will
range
an
to
an
volumetric
of
for
1020ppm
to
of
application
3.32
Eqn. The
19.5ppm
was
concentrations
sediment
the
the
velocity.
of
value
for
3.32),
0.0mm
(3.33)
dk°
(Eqn.
of
roughness
-
that
suggested
equation
6.28D(d+k, C,
D 4.80 k°
1
Suki
Mat
pipes.
rough
43.13(1+ k°)
d+k°
(TS. -1)d
for
°°
k
V=3.73
1
0.50
0.5),
and 9'b, is
and his
representing
0.32
< 408
< Y/D
entire
data
(1991)
deposition
in
measured
a. 305mm dia..
with 60
the
mobility
The
experimental
(m/s)
< 0.668,0.2
0.294
""
:" , ýý
1v
ý
,,
ý!NI, ilýjilý, IýIý! 'iili!üli's! ºýiitiýliiijliill-ýliliili 1 11 12 13 14 15 16 17 18
34567891 2 ý, ý4.000 PLATE 4.4a
Pipe
wall
roughness:
Roughness
1 (sand
size
d50 = 0.5mm)
ý Fýý ý,
yy
h.
r
.ýy .
S.
.
ýC Y
i
2
FS 910
34
PLATE 4.4b
Pipe
wall
roughness:
11 12 13 14 15 16 17
Roughness
81
.r1
2 (sand
size
dS0 = 1.0mm)
.6
of
the
White
equivalent
4.2
dso (mm)
each
the
invert
was
obtained
2
1.00
1.34
level
improve
minimum
were
by adjusting
the
flow
at the
and
taken
was
criterion
-
found
flow
to
flow,
is
give
was when less
the
tail
adjusted
necessary.
taken
than
flow
the
The
if
flow
required
and
jack
the
using
The
position
the
be uniform
set
discharge.
levels
Sp]/Sp)
was
recorded.
of
water to
pipe
opened
uniformity
([Se
difference
a fully
maximum
was
the
of
slope
readings
initially
fixed
(mm)
0.53
the
ROUGHENED
VALUE
0.50
test,
For
ko -
ROUGHNESS 1 ROUGHNESS
at
each
absolute or
equal
depths
within
and depth
gate
was
later
on
A set
of
point
gauge.
relative
slope
5%.
to +/-
This
2mm from
mean value.
The effective to
Colebrook-
AVERAGE
SAND SIZE
WALL
CONDITION
the
the
VALUES OF ko FOR AN ARTIFICIALLY (D = 305mm) PIPE
AVERAGE
PIPE
The
from
pipe
equation.
TABLE
to
the
of
roughness
sand
the
water
slope, surface
So, was then slope
obtained
using .
equation:
82
the
by making gradually
a correction varied
flow
(Sp-Sf)
i_ dx
where
Sf is
slope
(Se).
the For
(S=S=Sf).
flow
the
be expressed
the
three
Experimental
After
uniform
flow rate
then
was
)(1
together
and
was
depths
were
flowY
discharge
Sediment
were
transport and
after
point
to
the
effective
by
to
flow
the
depth
readings
83
to
supply
limit
the
to
started
limit
of group
deposition
of
likely,
was to
adjustments
limit
The
the
flow.
the
ensure
to
added
occurred.
deposition
the
were
sediments
at
Necessary
at
Transport
possible
where
no
made
-F=)
sediments
as
move
ensure
rates the
be equal
(4.5)
deposition
dispersed
then
recorded.
the
close
as
as the
to
surface
should
uniform,
Sediment
until
sediments
minutes
several
before
reduced
allowing
for
obtained, rate
defined
deposition
After
was
an increasing
at
water
as:
Procedure
flow
the
slopes
nearly
was
So=Sp-(Sp-S.
4.2.6
is
dy/dx
and
flows,
uniform
Assuming
can
slope
(1-Fi)
gradient
energy
(4.4)
the
uniformity of
deposition were
made.
flow
the tail
of
for
gate
or
the
flow.
were
taken
The width
of
sediment
measured
along
the
4.3
Experimental
Details
of
summarised May
(1993).
4.3.1
Test
This
pipe
Work
the
test
here
are
Pipe
(see of
sections
-
Fig.
spun
450mm and
a total
by
three
up
thin by
plate
allow
pipe
horizontal The flume
and
from
reports
taken
450mm
locations
several
was and
an
pumps
and Plate
of
and
21m.
Flow
(1989)
and
2.52m
long
internal
diameter
of
supplied
to
was over
proportion
et
al
on wooden
position
were
flow
this
of
900mm x
two
a wide
blocks
checked to give
84
90mm slots
along
and
and
invert
adjusted
a maximum slope
the
of
the
levels
as of
pipe
extracted the
in
length
the
the
was
cut
the
rectangular
through
sediments
of bed conditions
be tilted
as
was made up of
recirculated
laid
could
procedure
May
a nominal
recirculated
had
by
4.5)
with
A small
section
experimental
Pipe
4.3
pump which
was
deposition
of
HRL
arrangement
length
observation
pipe
at
concrete
weir.
a slurry
Each
The
to
at
perimeter
wetted
limit
the
was adopted.
value
average
WQ, at
spread,
pipe.
top
to
pipe.
at
the
appropriate. around
0.01.
ýi 0e; U3ýý
ý3
äg
N
111
12
t
¢
C
o
Fc
.
ä
1ý
K&E
4 EO
ýa .
ä
ii Zý CL
a
J 85
ö
O
CD
co 1) 0
cd s.. C7
W EQ
a
86
flow
The to
act
tail
as
the
levels
were to
were
connected
point
gauges.
The
holes
were
tapping
to
A 1.22m
wide
test pumps
the
using
head was
Qw is over
the
given
by:
to
200mm above
made
half-full
at
thin to
used
weir
f low in
with
the
tappings
the
invert
and
above
required
flow
tappings
which digital
electronic
2.50m.
was
total >t;
discharge
the
addition
the
discharge
upstream from
the
of
the
three
relationship:
,+3.521711 0.38927H
-1.5337
(4.6)
1000
rate cm.
the
over The
slurry
electro-current thorough
of
flow
only.
in
weir pump
m3/s
Hp is
and
discharge,
Qp in
Qp = (ECM - 2) x 0.003065
ECM is
The
the
allowing
located
weir,
plate
measure
following
the
where
used
were
allow
pressure
equipped
between
interval
Qý _
where
end
five
using
wells
stilling
rectangular was
pipe,
plates,
uniformity.
measured
be measured
depths
vertical
Techniques
Measurement
The water
flow
two
of
downstream
the
at
gates
for
adjustment
4.3.2
made up
restrictors,
the
meter test
Q,. and Q..
87
pipe,
readings Q (m3/s),
the m3/s,
(4.7
in
volts. was
given
The by
The
digital
counter
made
the
and
varied
was
slope
pipe
by
the
of
to
connected
(4.8)
Sp = 9.964 x 106 FSCR - 0.00314
FSCR is
where
The
the
temperature
upstream
reading.
counter
kinematic
The
a thermometer
using
was, measured
tank.
was
readings
counter
a
from:
calculated
was
slope
a mechanical
Calibration
reading.
jack
viscosity
the
from
obtained
was
in
placed
Eqn.
4.3.
Sediment
was
sediment
the
test
sediment
pipe
Supply
on
sediment
return
the
source
of
outside pipe
(see
detected
with
(=d30)
size
2.62.
and Discharge
in
by the
head
the
hopper
the
and recirculated to
sand
narrowly-graded
introduced
concentration
attached
light
a
gravity
pipe
return
The sediment
the
was
specific
and
4.3.3.2
of
used
sediment
0.72mm
The
Characteristics
Sediment
4.3.3.1
The
Sediments
The
4.3.3
of
was measured of Fig. the
a
im 4.4). signal
88
test
using
long The
the
pipe.
an infra-red
perspex
section
sensor
mounted
which
end
pump through
slurry
the
downstream
the
at
were
modified
sensor of
the
opposite by
the
FIG. 4.4
Sediment
sensor
89
(After
May 1993)
of
amount
sand unit
an amplifier to
passing
the
along
The
pipe.
through
was connected
which
signals
fed
were
to
a voltage-converter
a counter.
Before
the
infra-red
in
weighed
the
a
base
the
catch
slurry
return
the
required
and
a stop
at
pipe
hydraulic
The
calibration could
be
curves,
of
is
shown
the
sediment
Uniform
tests
clear-water roughness
curve in
clear-water
or
into set
more
holes,
resealed
at
taken
at the
and
sediment
Fig.
the
pipe
were
for
to
return
4.5.
Using in
concentration
the
determined.
Establishment
of
then
at
directly
return one
pre-
vertical
sands
readings
were
calibration
1.39m/s
of
sensor
holes
The
from
removed
Ten
started.
it for
sediment
a
and
the
holes
hopper
the
over
readings
the
was
with
carry
introducing
with
tape
was
velocity
appropriate
A series
Then
was stopped.
stopwatch
4.3.4
before
sensor
sizes
The
a funnel
and
carried
various
filled
with
beaker
the
recorded
100s.
of
from
of rates.
mounted
pipe,
The
velocity,
intervals
then
intake.
pipe.
watch
was
test
the
of
the
and
were
supply
beaker
and It
concentrations
holes
of
the
calibrate
calibrations
with
a range
over,
sands
pump were
beaker,
sands.
end
sediment The
allow
taped
downstream to
to
to
was necessary of
range
plastic
of
it
velocities.
pipe
amount
sediment
test
over
the
conditions
pipe
sensor
initially
were
pipe
be used
a 2-litre
using
drilled
the
could
return
sediment out
system
of
the
Flow
were test
carried pipe,
90
and
out also
determine
to to
improve
the the
O
0 0 0
U O .r, Co 9.1 .0 cd U C) Cd
. r. eo q b cý aý c, c. 0 q a) cr
m
ci LO
CD
A LU
CD
(s)
L()
ýf
d'
Cl
Cl
NN
(cui/fix)
0 m
CD U)
CD G)
©0
"-
LIone. puaouoo
91
U)
pyres
mý
V 'd
la)
2 'd Q) c
w
flow were
return
the
upstream
end
a length also
raised
the
upstream
end
as the
flow
by
PVC plates
two
The and
and
slope
were
flow
up
flows
was
at
section
of
12m from
the
limit
of
channel
the
floor
at
flow
depth
were
considered
supported
half-full
of the
required the
of
flow
uniform the
when depth. Eqn.
applying
flume.
the
adjustments
required
by
taken
was
depths
uniform
the
function
of
until
to
was
as to
tested,
made
was with
This
also
The
wall
diameter
plate.
necessary
for
Procedure
Transport
A test
the
channel
pipe
and
that
such
point
Any 4.4
to
pipe was gauge
effect obtain
of the
So.
Experimental
4.3.5.1
to
each
± 2mm of
within
slope,
4.3.5
For
were
pipe.
conducted
and
test
channel
fixed
restrictors
non-uniformity
effective
the
the
were
readings flow
set
test
were
full.
The
obtained.
about
tests
was
the
the
which
the
at
replaced
4.6)
The
the
flow
then
Plate
pipe.
to
the
was
a semicircular
with
to
three-quarter,
discharge
test of
escaping
entrance
clear-water
the
bend
(see
sediments
connected
restricted
The
channel
three-quarter closed
bend
pipe.
inside
from
sands
test
the
bend
a
the
semicircular
to
up
any
avoid
the
of
150mm was
of
via
pipe
However,
pipe.
a 600mm long
with
test
Initially
end.
upstream
the
to
returned
sediment
the
at
conditions
two
the
Limit
2.52m
upstream
deposition
were
Sediment of
long end was made
92
Transport
Deposition
sections chosen. along
the
of
this
The test
pipe
observations section
located of while
W
rJ
.C
vi
a,
ý-, Z
the
length
whole
local
depositions
Once
the
to
added
clear-water
the
hopper
were
each
equilibrium
was to
section
5-10
seconds
interval
reached.
Two
taken
were sets
flow
of
when depths
limit
of
was
taken
to
made
limit
at
the
at
deposition
the
not.
100 was
between
taken
also
at
test
or
readings of
be
Once
deposition
of
were
the
readings.
sensor
the
deposition
constant.
limit
sediment
of
the
readings.
sensor
Transport
4.3.5.2
The
loose
test
pipe
beds up
for
levelled high
consecutive
gradually
sensor
were
the
was at
to
been
the
were
observations
flow
the
up
flow
readings
sensor
had
were
limit
from
the
rate,
obtained,
if
see
of
series
the
rates
continuously
occur.
readings
the
that
ensure
not
sediments
until
transport
supply
when
A
The
monitored
equilibrium
the
4.3)
Fig.
did
sensor
sediment
to
checked
joints
conditions, (see
sediment
always the
at
and
reached.
deposition At
slope
for
been
had
was
pipe
especially
pipe
recorded
the
of
were to
After adjusted
bed
the to
the
raise
to
the
filling
by setting
been water
the
thickness,
required
flatten
has
Beds
by
prepared
each test
discharge
Loose
over
the
whole The
y,,.
flume
the
at
length bed
a steep
of was
slope
the then
and
bedforms.
levelled, levels
94
the to
vertical
preserve
the
plates flat
bed.
were The
flow
discharge
velocity)
was then
adjusted
to
bedforms,
the
required (V=
-
0.7m/s),
flow
sediment
flow
depths
the
readings
were
pumps
pipe
bedforms. upstream bed
width
4.5)
at
and
last
portable
flume
slope
uniform
flow.
for
uniform
It the
(depth
and vertical
plates
Due flow
was
the set
for be
could
criterion
to
that
observed
was
conditions
were
presence
of
± 5mm of
at low
set
and
the
velocity ± 2mm of
at
the
depths.
sensor were
been
vertical
was
left
Due
10cm
in
to
the
/or
point
gauges.
point
gauge.
The
Once
readings. end
sediment
drain
disturbance
over
sensor
was
pump
and all by
sealed the
and
flow
order.
to
ends
intervals
1000s
over
downstream
The
that
thickness
intervals
the
the
taken,
overnight
and downstream and
between
plates.
down
shut
taken
were
readings
recorded
had
the
closing
The
criterion depth.
Five
The
obtain
flow
required
set.
flow
0.5m/s
required
the
at
followed of
the
of
were
the
length
the bed
95
thickness
bed
near
measurement
of
sediment the
pipe, made
by measurements
at
each
of
10m between was
slot
(see
measured
of the the Plate
the
first
using
a
5
CHAPTER 0
ANALYSES
PRELIMINARY
5.1
Flow
Resistance
This
section
provides
theoretical
works
is
to
relevant
(1988),
Featherstone-Nalluri
5.1.1
Clean
flow
The in
of by
flows, hydraulic
for
open
Darcy-Weisbach replacing
radius
frequently
I
is
that
channels
can
be
in
found (1979),
Schlichting (1993).
Chadwick-Morfett
and
channel
known used
flows
diameter,
pipe
Manning's
is
developed
equation,
D,
*
with
usually for four
expressed pipe-full times
the
(4R):
AV2 88R
as
Darcy-Weisbach's
equation
is
the
(5.1)
friction Manning
I R4' Son
n being
works
(1966),
Chow
S_
where
in open
These
and
experimental
Pipes
resistance
terms
as
such
to
resistance
studies.
present
textbooks
standard
flow
regarding
the
introduction
a brief
roughness
factor.
"-96
factor.
Another
equation:
(5.2)
An
approximate
5.1
Eqn.
through
and
5.2
Eqn.
rough
carried
out
flowing
pipes
and
n
extensive
(5.3)
His
experimental
flow
regions:
laminar,
transition
turbulence,
and
turbulence
(further
divided
turbulence). boundary Karman
layer
by
flows
with
expressed
Nikuradse's
developed
and Prandtl
smooth
pipes,
log -2
pipes
Colebrook-White and
developed
Prandtl's
zones
and
-
rough
turbulent
of
experimental
to
results,
equations
von
which
were
2.51
(5.4)
FR.FX)
and
I-
rough
show
laminar
three
theories
and
as:
F)L
for
from into
semi-empirical
1=
for
their
combining
smooth
results
turbulence,
transitional
Later,
in
work
experimental
full.
turbulence,
obtained
RlX
distinctive
smooth
be
could
yielding:
n_
Nikuradse
I
between
relationship
where
k
is
conducted
log -2 3: 1D
the
experimental
a semi-empirical
equations,
for
linear
equation, the
transitional:
given-as:
97
(5.5)
height.
roughness
work
for
commercial
pipes
von
Karman-
verifying zone
of
turbulence
log -2
is
Eqn.
5.6
for
commercial
also
determined to
to
applicable
for
experimentally
open
flows,
channel
the
Reý
whole
the
of
type
each
of
region
application
into
4R
D=
k,
value,
For
pipe.
of
substitution
turbulent
roughness
effective
an
using
pipes
3.7D
+
2.5
5.6
Eqn.
yields:
log -2 VFT
Re = 4VR/v.
where 5.6
5.7
or
direct
It
must
to
be noted
that
iterative
necessitates
solutions
k+2.51 14.8R RoVII
the
(5.7)
Colebrook-White's for
solution (Eqn.
equation
5.6)
was
1.
Eqn. One
proposed
of
the
by Barr
as:
ký; 5 + 148R geý
log -2
after Fig.
5.1a
flow
in
5.1.2
The
D=
substituting shows a clean
Pipes
presence
composite
the
i. e.
a sediment
resistance
open
geometry
without
Deposited
to
application
cross-sectional
pipe
with
of
4R for
(5.8)
of
channel the
open
flows. channel
bed.
sediment
Beds
bed
made up
in of
pipes the
98
pipe
(Fig. wall
5.1b) and
produces the
loose
the bed
D 2 yo
FIG.
5. la
Cross-sectional
geometry
for
clean
D 2
FIG.
pipes
Y=ya+y8
5. lb
Cross-sectional
geometry
99
for
pipes
with
deposited
beds
(1987)
itself.
CIRIA
composite
roughness
linear
based
]ý_
P is
where
the
The
roughness. the
and
Another by
wetted
bed
approach
to (see
Visvalingam
shear
P.
the
of
'w'
(5.9)
and
ks is
and
'sb'
the
composite
refer
to
effective
the
pipe
wall
was
given
respectively.
the
compute May
composite based
1993)
on
resistance perimeter
weighting
of
stress: p*ýtlb
Tý=
where
weighting
perimeter
the
compute
+ P. pý+Pw
perimeter
subscripts
sediment
the
on
to
equation
k:
value,
roughness
an
proposed
is
is
the in
transformed
composite terms
+ pwTw
pt
shear
+ pw
stress.
friction
of
(5.10)
factor
Equation using
5.10
could
be
Darcy-Weisbach
equation:
P, PW), + h11eb w pab+ pw
"
where
1e is
the
friction
composite
(5.11)
factor.
,..ý . ., ýý
Aýt
ý. .
tý.,.
It
100
5.2
for
data
The
calculation in
given is
Appendix
listed
in
A total were
clean
(D
pipes
k0)
0.53mm
The
friction
in
the
factor
126
experiments two
with
Table
without
the
of
(Fig.
5.1a)
are
investigated
conditions
values
The
the of
(D
boundary
in
roughness Section
I.,
305mm
performed
was
corresponding
rough
values
of
from
computed wall
also
the
roughness,
ko,
5.7.
For
Eqn.
no were
and
4.2.4).
Colebrook-White's
Manning's
experiments
154mm,
=
were
4.2,
219
where
pipes
sediment,
5.1.
from
comparison,
preceding
details
The
conducted
clean
(see
Eqn.
obtained
was
A.
the
of
were
= 305mm)
Darcy-Weisbach's
those
geometry
smooth
other
1.34mm
and
Appendix
summary
Roughness
5.1.
out
and
The
Wall
including
cross-sectional
experiments
carried
450mm)
C.
Table
345
of
flow
the
of
in
given
are
Pipe
-
tests
clear-water
all
tests
transport
Results
Experimental
Clear-Water
computed
from
Eqn.
the
range
5.2.
In
general,
the
of
Reynolds
numbers
and
no are
(see
and
5.1a) have
0.009
pipes, higher,,.
-
the
Table
5.1. that
suggest values
0.010
_the.,,,.,
particle.
constant
over
overall
average
The
present
experimental
results
clean
flowing
the
of:, ko and
of
were
The
smooth
no in In
respectively.
mean values
than..
ko and-no
of studied.
in
given
Table
part-full
values
the the
ko (-0.53mm -sizes 101
range case and
.
(dso
pipes of
of
values
O. Omm -
the
1.34mm)
rough arIe
0.50mm ,
ko
of
0.2mm clean
slightly and,.
4.0
TABLE
a)
5.1
FOR CLEAR
WATER
DATA
SMOOTH CLEAN PIPES 305
154
D (mm)
450
V (m/s)
0.244
-
0.931
0.400
-
1.255
0.395
-
yD
0.149
0.756 -
0.206
0.803 -
0.500
0.750 -
k
NO.
0.73x1052.81x103
0.13x1051.49x105
Fr
0.49
So
0.13x10"? 0.51x10"2
0.06x10-2 0.53x10-2
0.02x10"? 0.30x10"2
0.01420.0465
0.03780.0928
0.1110.136
0.32
1.30
-
1.51
-
1.194
1.59x1034.69x105
Re
R (m)
b)
RANGES
EXPERIMENTAL
0.23
0.91
-
(mm)
0.169
-0.010
0.135
no
0.0098
0.0090
0.0103
0.01760.0426
0.01110.0224
0.01470.0204
57
OF DATA
111
51
ROUGH CLEAN PIPES 305 (ROUGHNESS
D (mm)
V (m/s) y ,,/D Re Fr So R (m) "k
0.390
-
(mm)
n ýö NO.
OF DATA
2.78x105
-
0.28
0.0324
0.0188
0.441 0.772
-
0.86x105
0.06x10-2
1)
1.109
0.174
1.22
-
0.56x10"2
-
305 (ROUGHNESS
0.0925
-
0.836
0.200
2.14x105
-
0.38
0.0368
0.756
-
0.62x103
0.10x10-2
1.02
-
0.56x10-2
-
0.0922
0.53
1.34
0.0111
0.0127
-
0.0322
90
0.0272
36
102
2)
0.0458
respectively) The
corresponding It by
calculated
values
resulted
in
ko and
higher
(ko = 0.0mm,
the
plots
pipes
smooth
full
curves
The
the
of
turbulent
5.4
Fig. 5.6-for
Eqn.
were
that
of
the
of
are
sensitive
(k0
ko
as
to
the
may have
pipe
data.
This
k0.
These
average
values
for
smooth
n, = 0.012)
clean
values
= 1.5mm,
0.012
(1987)
in
assessing
are
in
Fig.
5.2
rough
By
applying
pipes. for
5.1)
shown
each
set
Colebrook-White's
data,
of
Eqn.
5.6
for the pipe-
were
also
comparisons.
the
measured
computed
Reynolds
values
pipe-full for
data
fall
tend
be
to
An examination
curves.
numbers
experimental
I.
of
each
boundary
within
the
roughness transitional
zone.
tests
the
applicability
open
channel
flows
5.7.
Good agreements
obtained
equation
show
the
for
Table
using for
ranges that
shows
(see
plots
around
scattered
ko
computed
results
values
suggested
number
5.3
Fig.
of
the
on
shown
the
and Novak-Nalluri
Reynolds
and
values
average
and
practice.
Ao vs.
of
the
rough
and
(1984)
design
present
The
or
no=
by Ackers
used
pipes
0.010)
of
values with
consistent
5.7
part-full
average
0.011
that
Eqn.
the
are
n
noted
White's
1. for
of
no are
be
boundaries.
rough
artificial
Manning's
of
should
Colebrook
measured
the
create
values
respectively.
of
to
used
(Eqn.
confirming 5.7)
for
of in
using
Colebrook-white's
pipes
by
clean
(correlation
the
applicability
the
present
103
substituting
coefficient, of
the
experimental
Eqn. D= r=0.95)
Colebrook-White data.
4R
10-1
0 Egn. 5.6(k,
=0.0mm)
10
154mm (SMOOTH)
00000 D= 10 -0-110'
10'
10°
10'
to'
Re = 4VR/v
factor
friction
FIG. 5.2a Clear-water
in a smooth
154mm
dia.
pipe
10-' 1~ý
.c
Eqn.
5.6 (k,
= O.Omm)
10
00000 D=
305mm
10 a
10'
(SMOOTH)
lU 6
104
log
101,
Re = 4VR/v
FIG. 5.2b Clear-water
friction
factor
104
in a smooth
305mm
dia.
pipe
10"
Eqn. 5.6 (k, = O.Omm) 10
450mm
00000 D= lo-,
lU `
101
(SMOOTH)
to'
io'
in
a smooth
450mm
Eqn.
5.6 (k,
10
Re = 4VR/v FIG. 5.2c
factor
friction
Clear-water
dia.
pipe
10-1
o
.
0.5
01' 01 O
10
100 0
r.
a y;
10
CS I (SMOOTH) 305mm D= doo = 5.70mm (Limit of deposition) 10-11 0.1
1
V (m/s) FIG., 5.5d
Effect
of flow
112
depth
-
deo
5.7mm
10'
o20Q0 d6o = 0.46mm dßa = 2.00mm
Qoggp dao = 5.70mm F'
103 G/ a/
o/ *7/
O0
10`
/
I
a Vº
Of Oz
10
zo
1
D= 305mm (SMOOTH) /D ' 0.5 , (Limit of deposition)
10-1+ 0.1
i V (m/s)
FIG, 5.6a
Effect
10`
of particle
size: flow
depths
up to half-full
QD&= dao = 0.46mm #irir.*i do = 2.00mm ooQoo dao = 5.70mm
10'
10
ad v
dD ö
rr
10
"o
I
305mm (SMOOTH) 0.5 > o/D Limit of deposition)
D=
10-I 0.1
1
V (m/s)
FIG. 5.6b
Effect
of particle
size: flow
113
depths
more, than
half-full
5.3.4
Effect
The
of
effect is
velocity
the
transporting
hydraulic
in
wall
range
in
sizes
transporting
The
of
clean
pipes
was the
sizes
used
the
boundary
than
8.3mm.
sand
used
0.5mm
of
for
the
as
2.0mm
wall
Colebrookused
the
were
second
roughness
8.3mm
to
the
for
the
size,
sediments
1.34mm.
of
sand
by
as given
Similarly
height
of
up
transporting
to
in
There
is
or
decrease
1982,
Loveless be of:
coefficient with
5.7
to
tested,
no
clear with
wall
resulted
Hence
only
were
used
for 1991)
expected friction
increasing
those
that
the
increase
in
transport point to
indicate
sediment
in
out be
felt
between surface
114
that, data
experimental
around
trend the
5.10
the
be scattered
models
can
Figs.
sizes
seem to
Semi-empirical
increases
0.53mm
range
sediment
increase
roughness
height
as shown
range
(May
that
as
the
over
the
materials.
results
pipes.
made
roughness
the
sediment
larger
always
roughness
1.0mm
the
hydraulic
the
are
be recalled
must
the
self-cleansing
(d30 > k0).
1.0mm
of
It
pipes,
the
on
5.10.
to
clean
Therefore
equation.
roughness, in
rough
roughness
the
5.7
Figs.
itself
first
the
roughness
surface
material
height
roughness
White
in in
experiments
Roughness
or
wall
shown
for
For
Wall
of
the
of
for
rough
smooth
clean
velocity wall
will
either
roughness.
boundary
rigid
channels
that
an
increase
in
in
two
ways.
Firstly,
the,
sediment
roughness.
and
Secondly,
the
wall the
the the
wall flow
is
resistance
increased
sediments.
Both
transporting
capacity
suggesting
that
reasonable
to
boundary in
is
may point
The
suggest
presence
of
as
in
seems
the
with secondary
rigid
currents additional
direction.
f low
of
wall
resistance
roughness required
the
increase
in
friction
flows
it
creating
the
the
hence
pipes,
Although
in
designing
in
sediment
velocity
in
sediment
the
clean
1991)
effect to
reduce
the
(see
should
the
be
the
Rather
slope. factor
Section
not
on
other
due
5.3.7)
to
the
should
also
considered.
5.3.5
Fig.
Effect
5.11
of
pipes
works
in
confirming
small
pipe
5.11.
For from
existence
pipes the
regression, dia.
Pipe
shows that
large
data
due
on
needed.
opposite
the
acting
rough
an increase
the
that
consideration such
be
in
velocity
factors
increase
(E1-Zaemey
turbulence,
self-cleansing
is
required,
boundaries
results
for
flow
velocity an
assume
will
effects
the
of
a higher
roughness
rough
sole
these
of
drag
the
reduces
which
which
Size
the (eg.
best-fit has
the
of
parallel
154mm and distinct
interpolated
May 1982,
widest
on
Mayerle
collected data
range
of
lines
were pipe.
depending
115
is higher
from 1988).
the'data
450mm dia.
regions
required
velocity
results
line
comparison, the
limiting
the
is
for
experimental Using in shown
a power the
305mm
in
Fig.
also
plotted
for
the
These
lines
show
the
on pipe
diameter,
hence
D=
305mm
0.5 a oýD Limit of deposition)
10
0 0
ä
Ot*
Oll
10
a 1*
10
doo = 1.0mm k, =0.00mm
00000 k, =0.53mm I$S 0.1
1
v (m/6) FIG. 5.7a
D= 10'
d50 =
Effect of wall roughness (Flow depths up to half-full)
a/D
1.0mm
305mm > 0.5
Limit
of deposition)
10` a oý , 10
0h 0
*
dbo = 1.0mm k, =0.00mm * 00000 k0 0.53mm
1c 0.1
1
V (m/s) FIG. 5.7b. ß Effect of ýwall roughness d50 i. Omm = -(Flow , depths more than half-full) 116
305mm
D=
TjýD s 0.5 Limit of deposition)
10°
o
Qr i
C)
10
a w
t obi
1ö
A
0 10
Iý do0 = 2.0mm *-*.*A* k, =0.00mm 00000 k, =0.53mm 0000° k, =1.34mm
1$S 0.1
1
v (m/s) FIG. 5.8a
Effect (Flow D=
305mm
I o/D>0.5
10'
0
of wall roughness -d=2.0mm depths up to half-full
Limit
of deposition)
10`
of
°
10
2. Omm
d60
°o6eoo
*E*jrjr ko=0.00mm 00000 k, =0.53mm ko=1.34mra
i
1
0.1 v (m/s) FIG. 5.8b
Effect of wall roughness (Flow depths more than 117
d60 2,0mm = half-full)
D=
305mm ? o/D s 0.5 Limit of deposition)
i0'
OA CIA, ä
i0'
a
10 dN4.2mm k, =0.00mm 00000 k, -0.53mm äAAA k, =1.34mm 1$S 0.1
1
v (m/8) FIG. 5.9a
Effect of wall roughness (Flow depths up to half-full) D=
10'
a
d50 = 4.2mm
305mm
a/D>0.5
Limit of deposition)
10ý
ýýý 00
U
ýQ
ap
10
deo = 4.2mm *ý+ i+ k, =0.00mm 00000 k, =0.53mm aAaaa k, =1.34mm 1 0.1
1
V (m/s) FIG. 5.9b
Effect, of 'wall roughness d60 4.2mm = . (Flow depths more than half-full) 118
D=
305mm
0.5 c o/D Limit of deposition)
10 '
o0o
0*/
* öý° * ä
oA#l /o
'* ý,
10 '
a
0
10 d&o = 5.7mm k, =0.00mm
00000 k, =0.53mm oooao k, =1.34mm 1 -0.1
1
V (m/s) FIG. 5.10a
Effect of wall roughness (Flow depths up to half-full) D=
dbo = 5.7mm
305mm
(Limit o/D>0.5 of deposition)
10'
i 10ý
dm
ö
10
dao = 5.7mm '*
ýºi+ ko=0.00mm 00000 ko=0.53mm ko=1.34mm AAA
0.1
1
v (m/s) FIG. 5.10b
Effect of wall roughness (Flow depths more than 119
d60 = 5.7mm half-full)
different
that
suggesting
velocities
are
for
required
pipe
each
size.
5.3.6
Effect
Details
the
of for
5.1b)
(10m
long)
Fig.
5.13
with
a
that
for
a
inverts.
dia.
computed
with
The sediment
in
beds
might
The
author's
10%.
move
as
Fig.
5.12a).
However, trains
beds
sediment
of
for
smaller
separated
et
present are depths dunes
120
mean
yg/D.
al
1989,
present of over
when deposits, the
with of
presence
clean
data ys/D the
clean
the
E1-Zaemey
experimental
is
velocity
those
the
yQ.
implies
This
capacity with
of
capacity
lower
than
flow
All values
depth, a
by
section
5.12).
these
The
obtained
transporting
associated
C.
measured
Fig.
deposits
(May
were
the
be
1991).
than
in
transporting
width
continuous
on
the
bed
that
based
Appendix
the
concentration,
sediment
Loveless
y1,
(see
sediment
increase
in
given
pipe
(Fig.
geometry
along
sediment
sediment
pipes
bed
increase
the
given
are
thickness,
sediment
proportional
for
finite
then
illustrates
larger
required
of 450mm
the
were
beds
sediment
volume
of
parameters
with
mean
the
cross-sectional
deposited
with
the
averaging
of
computation
pipes
of
values
Deposit
Sediment
of
pipes of
a
1991, suggest
is
larger
sediments
inverts
(See
eQ
A
e
10'
$ o
°o
°e
e° ý
°
10`
A
+
A
a
ö 00
o00 o
10
$+ +
o+
SMOOTH PIPES
+
+
(Limit
of deposition)
°e°e°
D = 154mm
22449 D = 305mm +++++ D = 450mm
10-1 0.1
,
-,
1
V (m/s)
FIG. 5.11
10.,
Flow
direction
Effect
of pipe
size
Y0
5.12a Definitions FIG. of (separated features bedform
L
mean sediment dunes)
121
bed
thickness
and
direction
Flow
L'
r
Yo
Definitions 5.12b of FIG. (continuous features bedform
bed
mean sediment dunes)
thickness
* ýrCdr
10'
4
id-
°++
log P4
+
v++ox ° +
10
ocxx x
D450mm
ýx
x
xx 4c 'r` x WX x
x
xxxxxy. /D = 0.00 (Limit of deposition) dunes) oaooo y1/D < 0.01 (Separated dunes) +++++ y, /D = 0.05 Separated /D Continuous dunes = 0.12 y, 4_t**** D=0.22 Continuous dunes ' 10 ', 0.1
se
1
v (m/s)
FIG, 5,13
Effect
122
of sediment
deposits
and
5.3.7
height,
roughness 5.1
and
The
apparent
Both
the
computed
from
tested.
rough
pipes
for
to
of
be the
both
smooth
in
in
rough
larger The
pipes.
of
value
results
create
pipes
the
pipe
factor
for
smooth of
pipes.
clear
also
a
in
clean and
that
5.14
Figs.
friction
the
presence
increase
the
and
than
may
Eqn.
the
concentrations
smaller
sediments
to
shown
indicate
already
rough
due
is
pipes
increase
the
corresponding
Darcy-Weisbach's
factor
sediment
to
for
presence
clean
limiting
due
factor
of
> 1)
appears be
friction
the
and
respectively.
consistently
plots
of
5.7
the
case
However,
could
friction
in
(As/A0
range
sizes
the
were
Eqn.
the
factor
fiction
This
A1,
increase
5.15.
over
sediment,
Colebrook-White's
in
and
with k6,
sediments
Transport
Sediment
with
factor
friction
The
of
Factor
Friction
water
suggest
relatively
that
smoother
boundary.
increase
The is
in
shown
of
friction
Fig.
5.16.
author's
previous
half-full
flows, to
slots due
to
0.7m/s),
the
determining result, quite
passage
low,
It
and
hence
pipes
1990)
gauges
were
measurements of
dunes
of
ýs these
of
the
water
for
several
were
123
from
pipe
However,
velocity
accurately. the
the
at
(V
difficulties
caused
of
the
= 0.22
over
high
surface
omitted
ys/D
levels.
water
level
water
during
that,
where
at
deposits
sediment
mounted
especially
in of
with
be mentioned
Ghani,
point
slope
values
in
should
(Ab.
fluctuations the
the
the direct
obtain the
work
factor
experiments the
plot
> in
As
a
were shown
in
2.00
SMOOTH PIPES
&&A&&D=
154mm
00000 D=
305mm
+++++ D=
450mm
1.50 (xr/x0)
e
---------------------------------
r ------
Q --ö:, o
= 1.30
OCDý
A°
40.0
1.00 ooA 0JL ------------------------
------------------
= 0.85
0.50 10
1
1 oil 11 10
10
10'
10'
C. (PPM)
FIG. 5.14
Increase in friction (Smooth pipes)
factor
at limit
of deposition
2.00 D=
305mm
00000 k, =0.53mm ýooAA k, =1.34mm 1.50
1 20 -------------------------------------------------0 00
0
ao
o
1.00
-------------------
I-=0.93
0.50
1 .11
10
los
10'
C, (ppm)
FIG. 5.15
Increase in friction (Rough pipes)
factor
124
at limit
of deposition
io
Appropriate
5.16.
Fig.
have
level
water
measurement
for
5.16
Fig.
Overall, < 1%) the larger
value
(May
made
the
measurement
1993).
The
water
as
explained
is
studies
present
be
of
the
of
level in
for in
increase
shows
Froude
depths
small
of
roughness.
This that
that
is
suggests
definitions shown
> an
with
hence
the
of in
the
Fig.
were height 5.12.
the
around
those
of
with 1%
=
for
an earlier be
would large
the
attractive
very the
of
pipe
clean
May et
of
al
for
a new
studies.
The
pipes.
also
made for-the
and
length
The
corresponding
125
For
values
work
the
roughness
roughness.
5%,
the
corresponding
Froude
a
ye/D
depth
of
a larger
However,
(ye/D
deposits
factor,
friction
pipes.
large
depth
a small
composite
clean
of for
expected Also,
Fig.
the
for
that
shows
that
than
5%).
as
been
the
4.3.2.
Section
to
adjustments
since
method
to
of
present the
individual mean
values
dunes
are
of
the
0.1 ++++ +
KX
XKO
'ýi`'
I
, 0,4.
+++Q
Ck
X
0.01
D = 450 mm (Limit deposition) /D 0.00 of = xxxxxy, dunes) (Separated /D 0.01 < 0000o y. +++++ y, /D
Separated Continuous Continuous
= 0.05 = 0.12 00oao ye/D /D = 0.22 *sý y.
dunes) dunes dunes
111411
0.001 10"'
10'
10
1
jIIIII10`
10'
C, (ppm)
FIG. 5.16
factor
Friction
beyond at and
the limit
of deposition
15.0 12.5
450mm
°D=
10.0
/D 00000 y. +++++ y. /D eo°eo y. /D ***** y. /D
e *°
7.5 5.0
++
54 .
+* eir
2.5
+
0.0
it e
< = = =
dunes) 0.01 (Separated dunes) Separated 0.05 dunes Continuous 0.12 dunes Continuous 0.22
e
+++
ko=0.135mm
---------Qa-----------------------------------
-2.5-5.0
0.0
1.0
0.5
Fr = (BV2 /
FIG. 5.17
1.5 a )o. gA
Effect of Froude number on overall in pipe with deposited beds
126
2.0
flow
resistance
height
length
and
averaging
sediment
the
simplicity, the
compute
values values
corresponding computed show
the
Visvalingam
from
TABLE
of
bed
of
the
AIeb and
of 5.3
5.7.
ksb with
the
Froude
450mm
keb,
were 5.19
and Fr.
number,
CHARACTERISTICS: FLOW RESISTANCE WITH DEPOSITED PIPES BEDS
D=
the
while
5.18
Figs.
to
used
was ABb,
its
to
height,
roughness
depth
each Due
5.11)
factor,
Eqn.
for
the
of
range
5.3.
(Eqn.
friction bed
The dunes
the
Table
method
Colebrook-White's
variation
of
by
obtained
was
dunes.
in
given
test
each
length
and is
deposit
for
individual
the
of height
the
of
mean values of
values
all
dunes
the
of
-
dso = 0.72mm
y3/D
< 1%
5%
12%
22%
Ab
0.0253 0.0349
0.049 0.116
0.038 0.111
0.011 0.108
ksb
0.62 - 37.20
16.60 208.50
6.40 130.00
H (mm)
14 - 22
38 - 69
25 - 83
51 - 74
L (MM)
192 - 367
400 - 633
505 - 940
1090 - 1272
7.20
98.70 -
NOTE:
For bed thickness flow proportional
of 0.22D, the bedform measurements depth (Y/D)'of 0.75 only.
127
were made for
overall
11
nA
+
o+
A
450mm
D= °
°ODOD y. /D /D +++++ y, /D 00000 y, /D **
°
0.01
1.0
0.5
0.0
of Froude
Effect
2.0
1.5
F= = (BV2 /
FIG. 5.18
< = = =
dunes) 0.01 (Separated dunes) 0.05 Separated dunes 0.12 Continuous dunes 0.22 Continuous
a )o. gA
on the bed friction
number
factor
+
100
+ °+e* it
+e $
°F e
10 ý"
o
0
D=
i °
o000o y1/D < 0.01 (Separated +++++ y. /D /D y.
= 0.05 = 0.12
y. /D = 0.22
*+ý 0.10.0
450mm
0.5
Separated Continuous
Continuous
1.0
dunes) dunes) dunes)
dunes)
1.5
Fr = (BV$ / 9A )o.a FIG. 5.19
Effect of Froude number
due to sediment
bed
128
on flow resistance
2.0
6
CHAPTER
6.1
The in
Background
basic
and
steady
(V)
(p)
density
of
concentration
due
acceleration
These
variables
works Sakhuja have
a
number
(Ambrose 1990) great
pipes.
Several
Chapter
3 are
(D)
usually the
1953, have
prediction
identified
examples given
in
channels
(R),
flow
mean
(v)
viscosity
density
bed
of
analysis
(p9) (k0)
of
and pipe,
(So)
slope
and
the
of
these
Table
6.1.
129
ways
to
the
flow
transporting
of
used
obtain
Mayerle these
sediment
Previous
parameters
1988,
parameters
transport as
a
to
extensively
parameters.
1975,
several on
two
was
group
Novak-Nalluri
influence
pipe
roughness
in
applied
dimensionless
of
and (I. ),
dimensional
Firstly,
capacity.
(d),
size
process
(g).
gravity
were
kinematic
sediment
enabling
relationship
obtain
to
('fo),
size
with
clean
radius
water,
sediment,
in
hydraulic
stress
shear of
factor
friction
or
transport
sediment flow
surface
(yo)
depth mean
or
the
govern
free
uniform
flow
the
velocity and
that
variables
include
to
DATA
Pipes
Clean
6.1.1
TRANSPORT
SEDIMENT
OF
ANALYSES
process highlighted
Paulknown in in
The
second
at
the
approach
was
(May
equilibrium
homogeneous
dimensionally being
to
similar
solve
the
forces
1982,
Mat
Suki
those
1987,
by
obtained
on a particle Loveless
equations
are
dimensionless
their
with
acting
These
equations.
semi-empirical
yielding
to
usually
parameters
dimensional
the
1991)
analysis
approach.
TABLE
6.1
PARAMETERS FOR CHARACTERISTIC CHANNELS CLEAN PIPE
TYPE OF
SEDIMENT
DIMENSIONLESS
TRANSPORT
GROUPS
PARAMETERS MOBILITY
V1
ti,
gd5(S,-1)
v V'
TRANSPORT
pg(S.-1)dso
CVR -l)-4 vlg-(-Sa --
SEDIMENT
CONVEYANCE SHAPE
FLOW-
Dgr,
R/dSo,
D2/A,
CBs
RESISTANCE
130
d50/D,
yo/dso,
(ks
-
S8
Dh/yo,
ko) /D
Yo/D
IN
The a
the
values
of
standard
6.1.2
present
5.2)
were
to
3.3.1).
This
(V),
as velocity
involved
hydraulic
performance
in
of
plot
of
observed
A
discrepancy
computed
and
measured
accuracy
of
values.
is
C,
size,
in
analyses was based
model
(adj.
the
of
clean
pipe
r2),
model.
of limit
the
at
other
radius
(R),
several
of
computation
using
(see
channels
applicability
the
(Cv)
The overall
of
the
existing (see
deposition the
of
measured
Table
volumetric
quantities
and
friction
is
presented
such
factor
with
(1a).
sediment
a
and
coefficient
simplicity
transport
concentration
sediment
the
evaluate
sediment
by
Equations
data
experimental
for
equations Section
Existing
of
used
the
preceded
regression
best-fit
the
determination and
were
relationships
multiple
of
selection
(s)
Appraisal
The
by using
adjusted
deviation
transport
existing
final
The
data
experimental
was obtained
equation
extensively. on
present
the
of
comparison
final
the
of
analyses
Dgr,
investigators
equations
plotted
as
experimental presented,
is
values, Here,
a
the
function
introduced
It
data in
1993,
in
Section
should
Loveless
the
appraisal
3.3.1.
131
between
ratio
ratio
dimensionless et
computed
indication
an
discrepancy
by White
relationships. 1982
as
the
of
the
as
used
graphically their
against
defined
ratio,
an approach
(May
equation
concentrations
equation.
transport
alluvial
their
the
each
al
(1975)
be noted 1991) of
have several
of in
the terms
sediment to
assess
that
other
also
used of
the
The
of
categories
were: 3.15,
and
Eqn. be
should
In
pipes
were
effect
of
and of
the
are
the
or
surface
given
in
percentage
variation
of
Eqn.
experimental
50ppm
is and
concentrations
Eqn.
The
second In
(1982)
conjunction
Vc.
velocity, were
transport
Eqn. Novak-
with
equations
sediment
on
analysis.
threshold
the
3.11
in
data
500ppm. using
rough
beds
It
selected
equations
6.2
and
in
terms
of
which
can
Fig.
good
at
of
be found
clean
highlight
results on
average
for
the
Figures
each
the
of 6.1
is
equation
discrepancy
ratio
different
ranges
in
ratios.
6.1(a)
provides
for-the
limiting
3.11
about are
132
within
fit
a reasonable
a mean discrepancy
Overall, Eqn.
to
plotted
performance the
data
The
overall
with
--
present
roughness.
discrepancy
the
rather
and
Table
data
of
the
equations, smooth
statistically
agreement
in
these
of the
of
into
6.2,
Table
Laursen's
all
the
of
wall
presented
the
compute that
grouped
comparisons In
3.19
based
(1975)
Macke's
were:
of
equations
3.35.
and
limit
deposition.
of
comparison
6.6.
to
selected
theoretical
equations
development
the
limit
the
3.5
3.34 from
Eqn.
is
Novak-Nalluri's
derived
(1989)
al's
the
broad
two
the
at
equations
category,
Eqns.
chosen
emphasized
denote
the
is
of
3.11,
(1988)
the
and May et
this
Eqn.
equations
category,
Nalluri's
to
(1956)
Mayerle's of
category
3.17,
In
the
represent
relationships
category
analysis.
Laursen's
comparisons
transport
first
The
dimensional
the
sediment
deposition.
this
for
chosen
equations
ratio
2.37.
of
concentration 55%
of 0.5
The
between
the' and
to
predicted 2
times
the
as
used
(see
values
observed
indication
an
transport
Fig.
similar
results
6.2
TABLE
6.1(a) for
band
This
the
of
of
reliability
(White
relationships
1981).
6.2).
Table
et
of 1975,
al
also
shows
that
Laursen's
both
rough
and
smooth
(predicted)
usually channel
alluvial 1979,
Yang
bed
Brownlie
3.11
Eqn.
produced
data.
DISCREPANCY RATIO (Cv) FOR DIFFERENT ALL PRESENT DATA (CLEAN PIPES)
Equations
is
error
EQUATIONS
(observed)
/
-
No.
of
Mean
min
max
0.91.1 (%)
0.751.25 (%)
0.51.5 (%)
0.52.0 (%)
data
2.37
0.17
33.82
10
23
42
55
256
3.84
0.14
61.20
7
17
31
38
256
3.55
0.01
41.10
5
12
30
35
256
Mayerle (Egn. 3.35)
0.38
0.02
10.41
3
7
21
22
256
May (Eqn. 3.19)
0.18
0.00
1.03
1
2
6
6
256
Macke (Eqn. 3.17)
0.24
0.00
3.04
1
5
14
16
256
Laursen (Eqn.
3.11)
NovakNalluri (Eqn.
3.15)
Mayerle (Eqn.
Fig.
3.34)
indicates
6.1(b)
limiting
at
produce
concentrations equation
itself
higher a
Eqn. for
concentrations
obtained can
that
values
over does
Dgr
3.29 2.0mm)
for
the
above
suggests
that
305mm (SMOOTH) D= (Limit of deposition)
10, I
'o
10
aý
0° a+ CIO
10 `
°
a+
o +* tr ýr o o°'
+ ° +
ö
o
*°
10
0
Ao
Sediment
size 00000 dbo = 0.46mm °°oo° dbo = 0.97mm ýrtrýr,a dso = 2.0mm
". " 1
+++++ dao = 4.2mm aaa°° 00000
10 "'
10`
10' 10' Eqn. 3.29 -
10 C, (ppm)
1
10"=
d6Q = 5.7mm dao = 8.3mm
FIG. 6.18 Predicted C, using Ackers' Eqn. 3.29 for (W8 10deo) dia. 305mm = pipe smooth
the 3.29
form
of
can
be
the
equation
re-written
be
should
K
and
J
respectively). that
it
will
m g-1
condition Fro. of
Figs.
defined
are
as
The
form no
predict
as given 6.19
Dgr and R/d50 for
Eqn.
Ackers'
re-examined.
as:
C, w
where
author's
of
and the
6.20 data
(Eqns.
earlier
the
equation
movement
by K is
(6.34)
of
larger
the
from
6.34) if
the
mobility
plots
author's
184
(Eqn.
sediment
than
show
3.30
total of
Frn/K
smooth
the
as
and
3.31
indicates threshold number, a function
305mm dia.
pipe
4.0-
D = 305mm (SMOOTH) (Limit of deposition)
0 3.0 o 0
0
2.0-
0 o
TRANSPORT 00 00
cA
o0
0 00
°
8
92
1.0
INCIPIENT MOTION
-
.2cc
L .
0
(9
0 NO TRANSPORT 0.0
ht
0
1114
1.,
fill
1111
111
11114114
100
50
oil
fill
1111
160
111
viol
11ij
250
200
Da total to critical Ratio of measured FIG. 6.19 mobility mobility dimensionless Eqn. 3.30 function Ackers' by as of a computed dia. data 305mm smooth particle size for authors 4.0
D= 306mm (SMOOTH) (Limit of deposition) o
3.00
o0
0
0000 2.0
0 cP o e000 (o oV o0®
00 o0
0TRANSPORT
0 0
00
INCIPIENT
1.0-91119
MOTION
0
NO TRANSPORT 0.0
0
50
100,150
200
250
R/dso FIG. 6.20 Ratio of measured total mobility by Ackers' Eqn. 3.30 as a function computed dia. data 305mm particle size in smooth 185
to
critical mobility of dimensionless
could of
in
bedforms
much higher
by the
be explained the
derived.
was originally
upon
channels
alluvial It
dueLthe
resistance
be noted
also
should
3.29
Eqn.
Ackers'
which
presence
that
the
range
10
Eqn.
Novak-Nalluri's ----
R- An
Fnn_
Ar% (Pra'a
3.5
vi v1 PO
10-1 1
10
loll R/d6o
FIG. 6.21 for loose
of
(Ackers
1991).
transport
in
6.23
clean it
suggest
author's
Since
3.5
data
the ýfor
is
3.30
the
the
to
whole
is
6.6)
Table
appropriate for
the
of
define
range
motion
150
within
majority (see
pipes
seems
Eqn.
Nalluri's
Eqn.
of
applicability
R/d50 < 100,
Comparison of incipient boundaries and rigid
of
R/d50
within
data the
K in
terms
Dgr.
Figs.
of
this
modification
smooth
305mm
dia.
pipe
were
30000
4.2mm with
predicted
the
data
determined
The
values
data
shows
the
data.
of
author
the
was
smooth of
for
as
equation.
Fig.
values
Hence,
coefficient
f(d30))
Ackers'
pipes.
observed-Fro
and maximum
the
that
modified
of
for
of
plots
Fro
with
presenting
in
for
analysis
preceding
was
May
parameters
an equation
equation.
correlation
given
values
in
1988,
in
f (dso))
errors
Ackers'
minimum
as the
as well
of
author's
accurate
clean
We (=
(Mayerle
relevant
of
the
of
all
The
form
more in
of
6.6.
the
is
value
given
The average,
majority
that
ranges
Table
proportionate
are
rough
shows
modified
analysis
was
in
process
the
the
minimise using
given
on
studies
other
the
variable
study,
each
1991);
transport
sediment
are
as
from
data
the
done
was
analysis
the
was obtained
>
data
from
TABLE
OF MODIFIED ACKERS' EQUATION VERIFICATION PRESENT CLEAN PIPE DATA (W. = 10dso)
6.20
D (mm)
RATIO
DISCREPANCY
r
FOR
NO.
s
AVERAGE
MIN
MAX
0.92
0.63
1.19
0.95
0.120
39
0.95
0.71
1.15
0.99
0.096
89
0.94
0.75
1.21
0.84
0.119
27
305 (ROUGHNESS 1)
0.97
0.72
1.21
0.97
0.126
71
305
0.90
0.73
1.11
0.96
0.085
30
154
DATA
(SMOOTH)
305 (SMOOTH)
,
450 (SMOOTH)
(ROUGHNESS
2)
' h .d Q>
/5'
.
,'
If
00
.0
of
uni
A
.0
G pip G
n G /
9 /
/o
,"
.' '
**
PIPE CHANNELS D = 154mm SMOOTH
o0 0° oD = 305mm 00000 D =4 50mm
oooao D = 305mm 00000D = 305mm
SMOOTH SMOOTH
ko = 0.3mm ko = 1.34mm)
i 1
10
(S, -1))°'6 - modified Ackers' equation FIG. 6.24. Verification of modified Ackers' equation for all present data with W, = 10dao V/(gds
191
the
author's
this
measurement
better
6.21
1.03.
and
0.5mm
the
This
suggests
and
depends
sediment
with
both
particle
and
on
Ackers'
= d50 for We =
dso = for
10d50
8.74mm.
The
values 0.91
Fig.
with
6.27
and
modified
sizes
of
shows
that
2)
We =
2.56mm
and,
a
of (see
illustrates Frm for Ackers' 0.64mm this
deviation
an of
width
Fr,
predicted
the
using
width
were
d50 =
1.05mm
-1.95mm,
for
dso =5.22mm
4d30 4)
for We =
an of
0.084.
of
the
0.72mm
0.135.
192
results 1)
needed:
with
discrepancy
ratio
data.
application
both
(D = 300mm). ratio
measured
particle Table
of
-
these
of
The
We 3)
comparison
We = dso for
discrepancy
average
The
equation
average
requires and
0.12D
(1989)
al's
data.
Ackers'
6.22)
equation
effective
effective
results
(D = 158mm) gives
and
modified
May et
particle
size.
deviation
the
between
(1988)
Table
standard
of
0.94
Mayerle's
of
application
predicted
a standard
0.50mm,
We yields
of
for
values
d50 =
pipe
Table
of
sizes
the
We =
between
a function
dso > 4.2mm,
measured
equation
different
that
show
the
is
is
1)
used:
varies with
of
there
dso > 4.2mm.
ratio
width
results
that
clear
for
sediments
effective
compares
modified
for
The
We were
of
We = 0.12D
that
for
is
It
discrepancy
average
the
6.26
Fig.
2)
4.2mm,
while
size
of
that
6.25.
definitions
and,
6.19).
Table
see
Fig.
both
when
dso & 4.2mm
shows
in
shown
agreement
10dso for
of
are
analysis
Ws(
of
1.06
6.22 with
TABLE
6.21 VERIFICATION OF MODIFIED ACKERS' EQUATION'FOR PRESENT CLEAN PIPE DATA (W. = 10dso OR 0.12D)
D (mm)
DISCREPANCY
RATIO
r
s
NO. OF
AVERAGE
MIN
MAX
1.00
0.63
1.63
0.87
0.227
39
0.99
0.82
1.18
0.99
0.079
89
450 (SMOOTH)
0.94
0.72
1.21
0.84
0.119
27
305 (ROUGHNESS 1)
1.03
0.84
1.21
0.98
0.086
71
305
0.95
0.83
1.11
0.97
0.065
30
154
DATA
(SMOOTH)
305 (SMOOTH)
(ROUGHNESS
2)
V. = 10dbo : d60s 4.2mm W. = 0.12D : d50> 4.2mm
b
ý'
10 aý m
A(,) O'
0 PC)
/
,'
lh N'
7ý
O'
ol
tý+Q
I, YN Ö
G c,
fi
1ý
i .0
ýf 41
.
PIPE CHANNELS D = 154mm l SMOOTH aa00oD = 305mm SMOOTH 00000 D = 450mm SMOOTH 00000 D = 305mm ko = 0.3mm 00000D = 305mm k. = 1.34mm;
1
1
10
V/(gd60 (S. -1))°'° - modified Ackers' equation FIG. 6.25 Verification Ackers' eation of modified for all present data with W. = 10dba or 0.12T' 193
TABLE
6.22
VERIFICATION OTHER
AUTHORS
OF MODIFIED ACKERS' DATA CLEAN PIPE
RATIO
DISCREPANCY
EQUATION
r
FOR
NO. OF DATA
s
AVERAGE
MIN
MAX
MAYERLE (1988)
0.91
0.67
1.10
0.98
0.084
106
MAY ET AL (1989)
1.06
0.77
1.53
0.94
0.135
51
LOVELESS (1991)
0.96
0.54
1.15
0.95
0.175
46
MAYERLE (1988) DATA (Limit of deposition)
0
10
o' 90o Äö
00
w O
to
Q1
0
.' 1 '.
o6cPQ
AG
. -t
ý'
!d
,'
"'
o N iý' of
Ge
ýe.
yGt
' ox.
Sediment "'
.'
> o.
00000 °0000 ***** Xxxlex 00000 00000
0.50mm 1.05mm 1.95mm 2.56mm 5.22mm 8.74mm
sizes Wý W. W. W, W, w,
= = = = = =
dao) 4d60) 4d60 10dao) 0.12D 0.12D)
1 1
V/(gd0
10
(S,-i))°'5
- modified
FIG. 6.26 Verification of modified for Mayerle (1988) data
194
Ackers' equation Ackers'
equation
MAY ET AL (1989)
(Limit
ý 010. Oll
DATA
of deposition)
/0 0
10 ,.
**N
Sediment
sizes
G
F
ao
,' ,
***** *****
.' ý '
w, = da0 (W. = de0)
0.64mm 0.72mm
10 V/(gd5o
(S. -1))°'5
FIG. 6.27 Verification for May et al (1989)
-
Ackers'
modified
of modified data
Ackers'
LOVELESS (1991) DATA
(Limit
of
equation
equation
-' ''
deposition)
01,
J.
o 10-
/0ý/
.1
.0
01
o
'.
0 'o
.0ý ta'ý
cl
.. Gý
.
If
5
ý-ý GýQ'Q
.
ýý Dr
' .
"a o
.'
' . .'
,
Sediment 00000 0.45mm °0000 1.30mm 130000 O.00mm
sizes W. = d50) i'P. = 5d60) W. = 0.12D)
1 10
V/(gd60 (S.-1))°'6 - modified FIG. 6.28 Verification of modified for Loveless (1991) data 195
Ackers'
equation
Ackers'
equation
6.28
Fig. Ackers'
compares
found
d50 =
for
of (see
yields
on
modified 6.22)
it
four
modified noted
TABLE
6.16 the
of
application
0.5
of
as
given
should
We are in
be
to
with
in
clean
the
on to
particle the
apply It
)s
compute
EFFECTIVE We (m)
in
all
2.0
10d
d 200
available.
the It
extremes.
modified
clean
by
the
96% of ratio.
the
in
applicability such
the of
applicability
87% and
for
the
discrepancy
average
error
for
good
discrepancy
the
of
systematic
transport
when
the
agreement
average
between
applicability
the
for
ratio
94% of
the
where
agreement
1.00
the
within that
Within
the
between
90% and
C
and
over
discrepancy
reasonable
1.12
and
deviations.
(m/s)
V
varies
appears
that
obtained
A fairly of
and
± 0.25
the
0.50
lie
0.99
is
average
between
and
range
between
shows
of
ratio
this
within
1.02
deviations.
of
the
where
1.04
of
deviation.
agreement
good
1000
j
ratio
± 0.25
the
a
and
± 0.25
shown
discrepancy
an
analysis Ackers' that It
used.
(see
must
Ackers'
modified motion
the
criterion Fig.
6.21)
TABLE EQUATION
6.25 FOR MODIFIED ACKERS' DISCREPANCY RATIO (Fro) AS FUNCTIONS OF RELEVANT PARAMETERS - COMBINED DATA (CLEAN
Range of
parameter
Fr, Mean
min
PIPES)
(predicted)
/ Fr
0.901.10
max
(observed) 0.751.25
0.50 1.50
(%) (%) (%)
Dgr
No 0.52.0
of
data
(%)
10-25
1.09
0.67
1.62
40
78
96
100
156
26-50
0.97
0.66
1.39
51
93
100
100
103
51-100
1.00
0.83
1.40
89
98
100
100
56
101150
0.98
0.63
1.63
58
93
99
100
91
151-
1.01
0.86
1.13
79
100
100
100
24
201250
0.94
0.76
1.08
69
100
100
100
29
& 0.5
1.01
0.63
1.62
49
90
99
100
293
> 0.5
1.04
0.66
1.63
67
88
96
100
166
1-10
1.12
0.77
1.61
49
72
96
100
47
11-100
1.02
0.67
1.56
58
90
98
100
155
10150 0
1.00
0.66
1.62
57
92
99
100
186
501-
1.00
0.76
1.63
54
94
98
100
52
10012000
0.99
0.63
1.42
47
79
100
100
19
0.2000.500
0.95
0.63
1.39
47
90
100
100
59
0.5010.600
1.00
0.63
1.61
66
90
99
100
80
0.6010.700
1.02
0.76
1.63
60
92
99
100
99
0.7010.800' -
1.03
0.66
1.56
54
87
98
100
89
0.801900 .
1.04
0.76
1.62
61
90
97
100
62
0.901-
1.01'
0.77
1.54
51
96
99
100
49
1.17
0.78
1.53
33
67
100
100
21
200
y0/D
Pm) (
1000
V(m/s)
1.000 1.0011.500
200
ALL PRESENT DATA °O°O° Smooth pipes +++++ Rough pipes
2.0
a) +
+
ý
°
1.0
aft
Y
*°0 ,V
0.5
k
OTHER DATA *****
Ma erle
(1988
Loveless
(1991)
May et al (1989)
0.00
100
50
0
150
2
200
Dgr for
Discrepancy FIG. 6.30a ratio dimensionless function of a as
Ackers' modified particle size
equation
ALL PRESENT DATA 2.0
0oaao Smooth pipes +++++ Rough pipes OO
A
1.5 CC) #
1.0
Il
°
+ 40 %
10
13
U
19
°
13
i
+
-------
b
w
74
4. LU
+*
* *
RAO O'AUV +
-o---------
°
*oo°
.ý
0.5
aýý
°
*
ti
O
OTHER DATA
***** xxxxx 'ý** 0.0 0.00
Mayerle (1988) May et al (1989) Loveless 1991 0.20
0.40
0.60
0.80
yo/D
FIG, 6.30b
Discrepancy
as a function
ratio
of proportional
for
modified
flow
201
depth
Ackers'
equation
1,
ALL PRESENT DATA acooo Smooth pipes +++++ Rough pipes
2.0
oao 1.5
0130
xo
913 1313 ®a
o
aax
xp
oa4x
+ 1.0
-----------------c
ý x
---------ý
-+a
--------
--ý-o
CD
(1988)
Mayerle
*****
(1989) May xxxxx et al * Loveless (1991)
w
0
------
OTHER DATA
a ý
o
L
V
0.5
0
tý
it
-P
xx
.010 -1
10
1
10'
104
10
C, (ppm)
FIG. 6.30c Discrepancy ratio for modified concentration as a func tion of limiting
Ackers'
equation
ALL PRESENT DATA 2.0
00000 Smooth pipes +++++ Rough pipes o 00
1.5 o
ýr D
oa 113
0 00qo
a 0 °o okkk
ö
°
1.0
IV
öo°
4)
0.5
0
OTHER DATA ***** xxxxx *****
.0 0.0
Mayerle (1988) May et al (1989) Loveless 1991 0.5
1.0
1.5
2.0
V (m/s)
FIG. 6.30d Discrepancy. ratio for modified as a function of limiting velocity
202
Ackers'
equation
(1991) E1-Zaemey 6.1.3.4 Application of Channels Rectangular Bed Rigid and Introduction
6.1.3.4.1
in
As mentioned of
effect the
dry
during
and
can
the
more
likely
(1991)
proposed
transport
sediment
by utilising
a functional
relationship
)d
(b/yo)
to
depth
and
hence the
particular,
been
Paul-Sakhuja in
Eqn.
6.36
touched 1990, is
the
the
relative
by
change
describe
to
with
permanent
as the
dependent
deposits
variable:
1
(6.36)
bed
of
earlier 1991). particle
203
of
to
width
on
to
the
researchers
size
flow
and
In
movement. effective
width
concept
(Ackers
important (dso/D)
parameter
(b)
This
sediments.
Another
depth
width
sediment
be related
movement
Loveless
the
shape
could
on
the
yo
of
channel
bed width for
(W. ) responsible We have
the
remain
cemented.
s,
b,
influence
the
characterize
Cý,
=f
importance
the
emphasized
pipes
(Tb)
stress
S bl
He
in
in
properties
or
shear
pg(
sediment
of
especially
deposits
consolidated
process
bed
the
the
that
flow.
to
networks,
the
on
deposition
the
sewer
longer
The
become
eventually
E1-Zaemey the
flow.
weather
system
sewer
in
the
channels
pipe
resistance
flow,
of
nature
investigated
of
hydraulic
and
spasmodically
occurs
sediments
invert
the
on
capacity
intermittent
the
to
deposits
carrying
(1991)
E1-Zaemey
3.3.2,
Section
permanent
sediment
Due
Pipe
Clean
to
Equations
which
of 1984,
parameter reflects
influence
the
of
diameter
pipe
and
particle
size
on
pipe
with
a range
E1-Zaemey
(1991)
sediment
movement.
on his
Based of
bed
thicknesses
obtained by
an
the
for
application
functional
0.154
of
equation
in
data
experimental
of
multiple Eqn.
of
501ppm.
could
ratio
discrepancy
Eqn.
parameter
the
existence
found
be
for
tendencies
of
of
the
indicates range
data
lie
no
shows 'V
range
of
ratio
varies
that
=
0.94 the
± 0.25
that
0.98
the to to
Even range
generally the
where
1.09.
systematic
is
agreement sizes
to
0.25m/s from
the
particle
within
appears
6.54e
of
from
vary
ratios
presence
be
should
in
6.54c).
could be
can
inability
data.
discrepancy
Similar
overprediction as
the
average
respectively.
3.0
these
respectively.
concentrations
overprediction
(Fig.
the
the
an
ratio
for
for
Wt/yo
< 1% and
yd/D
and
of
and
6.54b
Fig.
plots
discrepancy
of
underprediction
10ppm
C,,
0.8m/s
higher
slightly be
could
the
obtaining
Eqn. 6.44 as a function
for
ratio
2.0
1.5
1.0 V (m/s)
FIG. 6.54e Discrepancy
the
(1992)
aaaaa perrusquia
average to
attributed the
of
slopes
of velocity
water
the
surface
accurately.
Eqn.
Overall,
This
beds. of
for
the
previously function
to
equation
An attempt
flow
highlights
was then presence in (Eqn.
the data
of
6.36)
pipes
with
another
consider beds
in
transport
254
over
of
function
to As
(1991)
cemented
the
q-
beds.
pipes.
E1-Zaemey
deposited
with
deposited
the
over
agreement
applicability
pipes
6.1.3.4, for
in
of
range
sediment
Section
good
conditions
from
made to
fairly
a
provides and
sediments
of
range
form
6.44
beds
account
mentioned proposed in
sewers.
a
the
Utilising
dependent
the
limiting
velocity
variable,
Eqn.
instead 6.36
V.
be emphasized
should
flow
of
effect
in
A multiple
the
regression
to
overall
friction
factor
r2
adj.
Table results
as
0.93
=
values
observed
data
the
on sediment
particle
size
of
The beds
sediment
AB.
parameter
data
combined
on
dso/D.
parameter
presence
to
considered
depth
and
the
is
(see
Table
produced:
with
The
f low
the
using
analysis
W1,/yo
and
by
6.37
shown where
the
gives in
96% of
discrepancy
Fig. the
functions
and
0.34
t2i Fig.
s=0.057. the
discrepancy 6.55
computed
an data
combined
6.55
average are
(6.46)
by Eqn.
terms
of
the
6.46.
Frs.
discrepancy
within
the
compares
values in
ratio
have
-0.31
The
ratio ± 0.25
of range
ratio.
applicability (Table
-01t
(0)
Fr® against
of
Wb
C0.16
8d(Ss-1)
of
as:
(6.4 s)
diameter
pipe
due
V=1.18
1.00
re-written
parameter
characterized
resistance
incorporated
6.34)
is
movement
sediment
of
as
stress
wb, DA
bed width
the
of
influence
The
movement.
is
influence
the
reflect
the
that
shear
Yo
ga, p(s1-1)
It
be
can
f CT,
the
of
of
6.34) of
is C,,
Eqn.
6.46
evaluated y6/D,
over with
Wb/yo,
the
the'discrepancy
Dgr and 255
range
V.
The
of
the
combined
ratio
plotted
measured
values
"TABLE
6.37 DISCREPANCY RATIO (Fr, ) FOR EQN. 6.46 (PIPES WITH DEPOSITED BEDS) COMBINEDDATA
Fr,
Source of data
Mean
(predicted)
0.901.10
max
min
/ Fr
-
(observed) 0.751.25
0.51.5
0.52.0
No. of data
(%) (%) (%) (%) 1.00
0.80
1.21
78
100
100
100
32
Alvarez (1990)
0.94
0.70
1.07
70
93
100
100
30
Perrusquia (1992)
1.06
0.77
1.56
68
97
99
100
79
0.96
0.69
1.30
42
94
100
100
52
1.00
0.69
1.56
62
96
99
100
193
Present
May (1993) Combined
PIPES WITH DEPOSITED BEDS Pd a,
'. , /'
14
'
10
09' l cab
o
*
13 ý1
ýG
,1
' ' ý. 1
00000 Present data Alvarez (1990) 00000 May (1993) 00000 perrus uia (1992
1
10 V/(gdeo(S.
FIG. 6.55
-
1))0.0 -
Eqn.
6.46
Bed load model for pipes with (Combined Eqn. 6.46 data) 256
deposited
beds
of
18 were
Frm.
The
Fig.
6.56a
from
results
0.90
falling
over
the
range
of
to
y, /D
of 1.02
Wb/yo.
transport
Fig. range varies of
6.56d
also
of
particle
Dgr falling
The
1.04
in
the
95%
the
of
within
for
pipes
the
1.05 the
deposited
good
agreement The
± 0.25
range
257
ratio.
good
over from
varies
each
each
range
the 1.00
of
W. /yo
and
Wb/yo
ratio.
of
C,,,
y8/D
in
the
sediment
beds.
obtained
average
95% of
over
for
discrepancy
discrepancy
with
good
discrepancy data
the
very
range
C.
of
reasonably
parameters
tested. with
of
for
each
varies
range
average
ratio
of
these
each
also
is
data
range
of
range
agreement
discrepancy
sizes to
± 0.25
ratio
ratio.
95% of
over
average
reveals
0.91
with
the
shown
process
from
studied.
importance
the
confirms
yg/D
to
correlation
for
is
± 0.25
the
discrepancy data
the
good over
discrepancy
of
6.56.
reasonably
the
of
values
Fig.
and
agreement
that
over
predicted
the
within
The
within
good
of
indicates
with
occurring
The
lying
is
90% of range
that
0.94
6.38
Table
The average
over
range
the
of
agreement
± 0.25
from
6.56c
range
the
with
the
whole
varies
Fig.
1.04
reveals
ratio
in
given
are
within
6.56b
computation
of C, studied.
to
Fig.
the
shows that
range
whole
in
used
of
the
for
the
discrepancy data
discrepancy
for
whole ratio
each ratio.
range
TABLE 6.38 AS FUNCTIONS
Range of parameter
DICREPANCY
RATIO
(Fr,
y/j
Wb/ yo
D gr
V (m/s)
6.46
PARAMETERS OF RELEVANT - COMBINED (PIPES WITH DEPOSITED BEDS)
Mean
Fr,
(predicted)
min
max
/ Fr
0.901.10
(%)
Co (ppm)
) FOR EQN.
DATA.
(observed) 0.75 -
0.501.50
0.52.0
(%)
(%)
1.25 (%)
No of data
1-10
0.91
0.74
1.16
30
90
100
100
10
11-50
1.00
0.69
1.21
67
94
100
100
36
si-100
1.04
0.91
1.30
86
97
100
100
29
101-300
1.02
0.72
1.57
67
97
99
100
101
501-1200
0.90
0.77
1.23
12
100
100
100
17