7/28/2019 47948988 04 Breakwater
1/263
7/28/2019 47948988 04 Breakwater
2/263
7/28/2019 47948988 04 Breakwater
3/263
7/28/2019 47948988 04 Breakwater
4/263
7/28/2019 47948988 04 Breakwater
5/263
7/28/2019 47948988 04 Breakwater
6/263
7/28/2019 47948988 04 Breakwater
7/263
7/28/2019 47948988 04 Breakwater
8/263
7/28/2019 47948988 04 Breakwater
9/263
7/28/2019 47948988 04 Breakwater
10/263
7/28/2019 47948988 04 Breakwater
11/263
7/28/2019 47948988 04 Breakwater
12/263
7/28/2019 47948988 04 Breakwater
13/263
7/28/2019 47948988 04 Breakwater
14/263
7/28/2019 47948988 04 Breakwater
15/263
7/28/2019 47948988 04 Breakwater
16/263
7/28/2019 47948988 04 Breakwater
17/263
7/28/2019 47948988 04 Breakwater
18/263
7/28/2019 47948988 04 Breakwater
19/263
7/28/2019 47948988 04 Breakwater
20/263
7/28/2019 47948988 04 Breakwater
21/263
7/28/2019 47948988 04 Breakwater
22/263
7/28/2019 47948988 04 Breakwater
23/263
7/28/2019 47948988 04 Breakwater
24/263
7/28/2019 47948988 04 Breakwater
25/263
7/28/2019 47948988 04 Breakwater
26/263
7/28/2019 47948988 04 Breakwater
27/263
7/28/2019 47948988 04 Breakwater
28/263
7/28/2019 47948988 04 Breakwater
29/263
7/28/2019 47948988 04 Breakwater
30/263
7/28/2019 47948988 04 Breakwater
31/263
7/28/2019 47948988 04 Breakwater
32/263
7/28/2019 47948988 04 Breakwater
33/263
7/28/2019 47948988 04 Breakwater
34/263
7/28/2019 47948988 04 Breakwater
35/263
7/28/2019 47948988 04 Breakwater
36/263
7/28/2019 47948988 04 Breakwater
37/263
7/28/2019 47948988 04 Breakwater
38/263
7/28/2019 47948988 04 Breakwater
39/263
7/28/2019 47948988 04 Breakwater
40/263
7/28/2019 47948988 04 Breakwater
41/263
7/28/2019 47948988 04 Breakwater
42/263
7/28/2019 47948988 04 Breakwater
43/263
7/28/2019 47948988 04 Breakwater
44/263
7/28/2019 47948988 04 Breakwater
45/263
7/28/2019 47948988 04 Breakwater
46/263
7/28/2019 47948988 04 Breakwater
47/263
7/28/2019 47948988 04 Breakwater
48/263
7/28/2019 47948988 04 Breakwater
49/263
7/28/2019 47948988 04 Breakwater
50/263
7/28/2019 47948988 04 Breakwater
51/263
7/28/2019 47948988 04 Breakwater
52/263
7/28/2019 47948988 04 Breakwater
53/263
7/28/2019 47948988 04 Breakwater
54/263
7/28/2019 47948988 04 Breakwater
55/263
7/28/2019 47948988 04 Breakwater
56/263
7/28/2019 47948988 04 Breakwater
57/263
7/28/2019 47948988 04 Breakwater
58/263
7/28/2019 47948988 04 Breakwater
59/263
7/28/2019 47948988 04 Breakwater
60/263
7/28/2019 47948988 04 Breakwater
61/263
7/28/2019 47948988 04 Breakwater
62/263
7/28/2019 47948988 04 Breakwater
63/263
7/28/2019 47948988 04 Breakwater
64/263
7/28/2019 47948988 04 Breakwater
65/263
7/28/2019 47948988 04 Breakwater
66/263
7/28/2019 47948988 04 Breakwater
67/263
7/28/2019 47948988 04 Breakwater
68/263
7/28/2019 47948988 04 Breakwater
69/263
7/28/2019 47948988 04 Breakwater
70/263
7/28/2019 47948988 04 Breakwater
71/263
7/28/2019 47948988 04 Breakwater
72/263
7/28/2019 47948988 04 Breakwater
73/263
7/28/2019 47948988 04 Breakwater
74/263
7/28/2019 47948988 04 Breakwater
75/263
7/28/2019 47948988 04 Breakwater
76/263
7/28/2019 47948988 04 Breakwater
77/263
7/28/2019 47948988 04 Breakwater
78/263
7/28/2019 47948988 04 Breakwater
79/263
7/28/2019 47948988 04 Breakwater
80/263
7/28/2019 47948988 04 Breakwater
81/263
7/28/2019 47948988 04 Breakwater
82/263
7/28/2019 47948988 04 Breakwater
83/263
7/28/2019 47948988 04 Breakwater
84/263
7/28/2019 47948988 04 Breakwater
85/263
7/28/2019 47948988 04 Breakwater
86/263
7/28/2019 47948988 04 Breakwater
87/263
7/28/2019 47948988 04 Breakwater
88/263
7/28/2019 47948988 04 Breakwater
89/263
7/28/2019 47948988 04 Breakwater
90/263
7/28/2019 47948988 04 Breakwater
91/263
Recent updates on parts of Conceptual design of Rubble Mound
Breakwaters
The papers can be downloaded from internet:
www.infram.nl under products&services and then publications.
Publication 1.A code for dike height design and examination based on wave run-up and waveovertopping.Update of sections 3.1 and 3.2
Publication 21.Effectiveness of recurve walls in reducing wave overtopping on seawalls andbreakwatersUpdate of section 3.2 pages 28-30.
Publication 22.Applications of a neural network to predict wave overtopping at coastalstructuresNew information on section 3.2.
Publication 20.Wave transmission at low-crested structures, including oblique wave attackUpdate of section 3.3.
Publication 2.Geometrical design of coastal structures
Additional information to section 3.3 on percentage of overtopping waves.
Publication 3.Application and stability criteria for rock and artificial unitsAdditional information to section 4.2 on probabilistic approach.Additional information to section 4.2.4 on effect of armour shape and grading.
Publication 5.Design of concrete armour layersUpdate of section 4.3.
http://www.infram.nl/http://www.infram.nl/7/28/2019 47948988 04 Breakwater
92/263
7/28/2019 47948988 04 Breakwater
93/263
1
BREAKWATERS I
UNESCO-IHE
Dr J.W. van der Meer
INFRAM BV
Contents of lectures
First day, 4 periods
Introduction
Functions, requirements,types
Cross-section Sheet show
Boundary conditions waves
Second day, 4 periods
Governing parameters
Hydraulic response
Stability formulae
Rock armour stability
Video
Third day, 4 periods
Concrete armour
Low-crested structures
Berm breakwaters
Toe and head
Video
Functions
House Breakwater
Shelter (rain, Protection against waves
cold, wind, heat Protection agains currents
Privacy Provision dock/quay
Comfort (sleep, Prevent channel siltation
rest)
Requirements
House
good location,position
roof, walls,windows
heating, airco
rooms
durable
costs
Breakwater
lay-out
permeability
crest level
access
lee side
reflection
Types
House
apartment
double house
single house
farm
factory
Breakwater
rubble mound
berm breakwater
monolithic vertical
vertically composite
horizontally composite
dams, low-crested
seawalls
(rubble) revetments
Boundary conditions
Soil bearing capacity; tests
Hydrographic data bathymetry
Water levels
tides astronomical tidespring tide
storm surge depression rise due toatmospheric pressure
wind set-up stress by wind shear
wave set-up by wave groups
7/28/2019 47948988 04 Breakwater
94/263
2
Boundary conditions: waves
Wave seconds
Sea state hours
Daily wave climate year
Extreme wave climate many years
Part of wave record
H
T
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.0 0.1 0.2 0.3 0.4 0.5
frequency (Hz)
Energydensity(m2/Hz)
P011
P013
P015
Examples of spectra
Wave heightsH1/3 = 1.43 m
H1/10 = 1.82 m
H2% = 2.00 m
H1% = 2.17 m
H0.1% = 2.65 m
H2%/H1/3 = 1.40
0
0.5
1
1.5
2
2.5
3
3.5
probability of exceedance (%)
waveheight(m)
100 90 70 50 30 20 10 5 2 1 0.5 0.1
Rayleigh distribution on deep water
Wave heights
H1/3 = 1.53 m
H1/10 = 1.75 m
H2% = 1.85 m
H1% = 1.94 m
H0.1% = 2.17 m
H2%/H1/3 = 1.21
0
0.5
1
1.5
2
2.5
3
probability of exceedance (%)
waveheight(m)
100 90 70 50 30 20 10 5 2 1 0.5 0.1
Double Weibull distribution on shallow water
One wave versus sea state
H H1/3; Hm0 = 4 m00.5
surplus: H2%; H1/10; Hmax
T Tm; Tp
surplus: Tm-1,0 = m-1/m0
7/28/2019 47948988 04 Breakwater
95/263
3
0
5
10
15
20
25
1 10 100 1000
Return period (years)
Hs
Bilbao
Sines
TripoliNorth Sea
Follonica
Pozallo
Examples of extreme wave climates (deep water)
From deep water to the coast
Refraction
Shoaling
Breaking
rule of thumb for gentle foreshore >1:50
Hs/h = 0.5 0.6
for breaker index: CIRIA/CUR p 211
Breaker index Hs/h (CUR/CIRIA)
sop=Hs/Lop=2Hs/(gTp2)
h=local water depth
Governing parametersbreakwater design
Waves
Hydraulic response parameters
Cross-section
Response of the structure
Waves
H1/3; Hm0; H2%; Tp; Tm; Tm-1,0
wave steepness: s = H/L = 2H/(gT2)
sop with Tp
and som with Tm
maxima: sop = 0.05; som = 0.07
breaker parameter = tan/s0.5
Hydraulic response parameters
Run-up: RuRu2%/Hs
Run-down: RdRd2%/Hs
Overtopping: q q/(gHs3)0.5
Transmission: Ct Ht/Hi
Reflection: Cr Hr/Hi
7/28/2019 47948988 04 Breakwater
96/263
4
Parameters rock
Nominal diameter Dn50
Dn50 = V1/3 = (M50/r)1/3 = cubic size
r= 2600 2700 kg/m3 (rock)r= 2400 kg/m3 (normal concrete
Concrete units: Dn
Relative buoyant density:
= (r w)/ w = 1.4 1.6 in most situations
Stability number
Hs/Dn50
Relation between wave
attack (Hs) and size of
unit (Dn50)
Rock shape Rounding of rocks
Examples of rock types Example of grading curve
0
10
20
30
4050
60
70
80
90
100
100 1000
Weight (g)
Percentage
exceeding
grading box 2
W15 (%) 234
W85 (%) 390
W85/W15 1.67
Dn85/Dn15 1.19W50 (g) 302
W50 cu rve (g) 30 3
7/28/2019 47948988 04 Breakwater
97/263
5
Example of shape curve
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4
largest/minimum dimension L/H
Percentagelarger shape box 2
> 2 L/H (%) 81
> 3 L/H (%) 4
Blockiness 0.41
Response of the structure
Damage level S
S = Ae/Dn502
number of squares that fit in erosion area
Damage level Nodnumber ofdisplacedunits in
a strip Dn wide
slope initial
damage
intermediate
damage
failure (under
layer visible)
1:1.5 2 3-5 8
1:2 2 4-6 8
1:3 2 6-9 12
1:4 3 8-12 17
1:6 3 8-12 17
Applicable damage levels S Damage level Nod
Damage parameter Nod: the actual number of
displaced units related to a width along the
longitudinal axis of the breakwater of one
nominal diameter Dn
Example: cubes 15 ton; Dn = 1.84 m; stretch 100 m long
Nod = 0.2 11 units In cross-section:
Nod = 0.5 27 units 20 units: 0.5/20*100%=2.5%
Nod = 1.0 54 units 40 units: 0.5/40*100%=1.25%
Nod = 2.0 109 units
Hydraulic response: run-up
Ru2%/Hs breaker parameteropRecent developments: o with Tm-1,0
Smooth slope: upper boundary
Reductions by:
roughness (rock!)
berm
angle of wave attack
Run-up rock slope compared to smooth slope
P>0.4
7/28/2019 47948988 04 Breakwater
98/263
6
Run-up rock slope: Weibull distributions
Hs = 2 m
Tm = 6 s
P = 0.4
0
0.5
1
1.5
2
2.5
3
3.5
4
0 1 2 3 4 5 6 7 8 9 10
breakerparameter o
waverun-upRu2%/Hm
0
Run-up smooth slope, very shallow water; Tm-1,0
Hydraulic response: wave run-down on rock slopes Hydraulic response: wave overtopping run-up
Wave overtopping: basic formula
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
dimensionless crest height Rc/Hm0
dimensionlessovertoppingq/(gH
m0
3)0.5
Q=a exp(bR)
b
a
1.E-07
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2
dimensionless crest height
dimensionlesswaveovertopping
Wave overtopping: breaking waves, all tests
0.1 l/s/m
1 l/s/m
10 l/s/m
100 l/s/m
7/28/2019 47948988 04 Breakwater
99/263
7
)1
H
R(-4.7
0.06=
gH
q
vfbops
c
opb3s
exp
tan
)1
H
R(-2.30.=
gH
q
fs
c
3
s
exp2
with as maximum:
breaking waves
non-breaking waves
Wave overtopping: general formulae Percentage of overtopping waves
Hydraulic response: transmission
Ct = Ht/Hi
Ct Rc/Hm0
and B, sop, Dn50
Change of spectral shape
Parameters wave transmission
General trend wave transmission; large scatter
for -2 < Rc/Hi < -1.13 Ct = 0.8
for -1.13 < Rc/Hi < 1.2 Ct = 0.46 0.3 Rc/Hi
for 1.2 < Rc/Hi < 2 Ct = 0.1
de Jong (1996) and dAngremond et al. (1996):
Ct = a 0.4 Rc/Hi
with a maximum of Ct = 0.8
and a minimum of Ct = 0.075
The parameter a describes all the other relevant influences:
a = (B/Hi)-0.31
* (1 e-0.5) * Astr
with: B = crest width
= breaker parameterAstr = a coefficient depending on the type of
structure:
rock slopes and concrete units: Astr= 0.64
smooth impermeable dam (asphalt) Astr= 0.80
impermeable smooth block revetment Astr= 0.80
block mattresses Astr= 0.75
gabion matresses Astr= 0.70
More accurate transmission formula
7/28/2019 47948988 04 Breakwater
100/263
8
Transmission, recent information
Large influence ofberm width is only
relevant forrubble mound structures
Smooth structures: no influence
New tests in EU-programme DELOS
confirm the formula
Spectral shape changes0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Relative crest height Rc/Hm0,i
transmissioncoefficientKt
B = 2 m
B = 4.5 m
B = 15 m
Influence crest width; smooth structures 1:4 slope
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.0 0.1 0.2 0.3 0.4 0.5
frequency (Hz)
Energydensity(m
2/Hz)
P014-Jonswap
P014a-PM
Incident spectra
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
frequency (Hz)
Energydensity(m
2/Hz)
P004
P005
Transmitted spectra
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
frequency (Hz)
energydensity(m2/Hz)
reduced incident spectrum
proposed transmitted spectrum
0,6m0,it
0,4m0,it
Transmitted spectrum; rough estimation Oblique wave transmission
Does Ct change with direction?
Yes!
Does direction change?
Yes!
Difference between rubble mound and smooth
structure?
For sure, treat them differently
Spectral change dependent on direction?
No.
7/28/2019 47948988 04 Breakwater
101/263
9
Hydraulic response: wave reflection
Hs/Dn50 = (KD cot)1/3
Limitations Hudson formula (1958)
the use of regular waves only,
no account taken in the formula of wave period or storm duration, no description of the damage level, the use of non-overtopped and permeable core structures only.
Hudson formula
for plunging waves:
and for surging waves:
0.5-
m
0.2
0.18
50n
s N
SP6.2=
D
H
P
m
0.2
0.13-
50n
s cotN
SP1.0=
D
H
Van der Meer formulae
0.5-
m
0.2
0.18
50n
s N
SP6.2=
D
H
0.5-
m
0.2
0.18
50n
s N
SP6.2=
D
H
Van der Meer formulae; influences
Van der Meer formulae; S N
N8000 maximum
Van der Meer formulae: Hs S
7/28/2019 47948988 04 Breakwater
102/263
10
Reliability
6.2 and 1.0 are stochastic variables
normal distribution
= 6.2 and 1.0 = 0.4 and 0.08 (V=6.5 and 8%) confidance intervals:
90%: +/- 1.6495%: +/- 1.96
Wave heightsH1/3 = 1.53 m
H1/10 = 1.75 mH2% = 1.85 m
H1% = 1.94 m
H0.1% = 2.17 m
H2%/H1/3 = 1.21
0
0.5
1
1.5
2
2.5
3
probability of exceedance (%)
waveheight(m)
100 90 70 50 30 20 10 5 2 1 0.5 0.1
Double Weibull distribution on shallow water
Shallow water: H2% or H1/10 better?
0.5-
m
0.2
0.18
50n
%2 N
SP7.8=
D
H
P
m
0.2
0.13-
50n
%2cot
N
SP41.=
D
H
plunging waves:
surging waves:
Shallow water equations
Minimum crest width Bmin:
Bmin = (3 to 4) Dn50
The thickness of layers:
ta = tu = tf= n kt Dn50
The number of units per m2:
Na = n kt (1 nv)/Dn502
where:ta, tu, tf = thickness of armour, under layer or filtern = number of layerskt = layer thickness coefficientn
v= volumetric porosity
=packing density
Crest width and thickness of layers
= /Dn2
Values of kt and nv (SPM, 1984)
kt nv
smooth rock, n = 2 1.02 0.38
rough rock, n = 2 1.00 0.37rough rock, n > 3 1.00 0.40
graded rock - 0.37
cubes 1.10 0.47
tetrapods 1.04 0.50
dolosse 0.94 0.56
Values of kt and nv
Under layers and filters
Geotechnical filterrules:
roughly: D15A/D85f< 4 5
SPM under layer:1/10 1/15 of W50A D15A/D85u = 2.2 2.3
Large under layer gives large P and
higher stability
Smaller under layer can be cheaper
7/28/2019 47948988 04 Breakwater
103/263
11
Design of concrete armour layersIntroduction
Hudson/Van der Meer (rock)
Two-layer systems
cubes
tetrapods
crest height
packing density
One-layer systems
accropode
core-loc
cubes
Overall view
3/1)cot( Dn
s KD
H =
Stability FormulaeHudson
Van der Meer - rock: plunging and surging waves
),,,( PNSfD
Hm
n
s =
Hs/Dn = stability numberm = breaker parameterS = damage level
N = number of waves
P = notional permeability factor
Concrete armour layers
cot =1.5 sm remains; m disappears
P = 0.4 (breakwater with under layer)
Damage level Nod
),,( modn
s sNNf
D
H=
Two-layer systems
Research 85 - 87
Cubes
1.0
3.0
4.0
0.17.6
+=
mod
n
s sN
N
D
H
Tetrapods
2.0
25.0
5.0
85.075.3
+=
mod
n
s sN
N
D
H
Cubes 15 ton; = 1.35; sm = 0.04; N = 3000
0
0.5
1
1.5
2
2.5
4 5 6 7 8 9
Wave height Hs
(m)
DamageNod
Formula
Hudson, KD=7
Stability formulae give damage curve
Recent research Research 85 - 87:
steep slope 1:1.5: no transitionplunging-surging waves
De Jong (1996):
MSc-student TUDelft
research WL|Delft Hydraulics
flume tests tetrapods
also steeper waves
influence crest height
influence packing density
7/28/2019 47948988 04 Breakwater
104/263
12
De Jong: formula for plunging waves
tetrapods
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 0.01 0.02 0.03 0.04 0.05 0.06wave steepness sm
stabilitynumberHs/Dn
Van der Meer (1987)
De Jong (1996)
plungingsurging
surging:
plunging:
f(Rc/Dn) = influence of crest height
Rc = crest freeboard
f() = influence of packing density
Na/A = n k (1 - nv)/Dn2 = /Dn2
Total formula for tetrapods
)/(s)(94.3+N
N.68=D
H 20.om
5.0
od
n
snc DRff
)/(s)(0.85+3.75=D
H 0.2-om
5.0
n
s
ncod DRff
N
N
Influence of crest height
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-2 -1 0 1 2 3 4 5 6 7
Relative freeboard Rc/Dn
Influenceofcrestheightf(Rc
/Dn
)
f(Rc/Dn) = 1.0 + exp(-0.61 Rc/Dn )
Influence of packing density
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.5 2 2.5 3 3.5
Stability number Hs/Dn
DamagelevelNod
= 1.02
= 0.95
= 0.88
= 0.48
Influence of packing density
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1 1.2
Packing de nsity / SPM
Reductioncoefficientf(
)
f() = 0.40 + 0.61/SPM
one layer: Bhageloe, 1998
One-layer systems
Advantages (accropode, core-loc)
strong units, no breaking; if breaking: 10% loss
no rocking: packed
under design: no damage! (safety factor)
accropode: experience of 100 constructed breakwaters
large saving in concrete
CHEAP AND RELIABLE STRUCTURE
Disadvantages
strict placing pattern (not always possible)
not yet much experience with core-loc
7/28/2019 47948988 04 Breakwater
105/263
13
One-layer systemsAccropode, core-loc, ..cubes
0
0.5
1
1.5
2
2.5
3
3.5
4
0 1 2 3 4 5
stability number Hs/ Dn
damageNod
accropode
start damage
failure
tetrapods
One-layer systemsAccropode
0
0.5
1
1.5
2
2.5
3
3.5
4
0 1 2 3 4 5
stability number Hs/ Dn
damageNod
accropode
start damage
failure
design KD=12
tetrapods
One-layer systemsAccropode and core-loc
0
0.5
1
1.5
2
2.5
3
3.5
4
0 1 2 3 4 5
stability number Hs/ Dn
damageNod
accropode
start damage
failure
design KD=12
core-loc KD=16
tetrapods
Overall view concrete units
Accropode Core-Loc Tetrapod Cube Cube
number of layers 1 1 2 2 1
slope 1:4/3 1:4/3 1:1,5 1:1,5 1:1,5
KD (breaking waves) 12 16 7 7 7
Hs/Dn = Ns 2,5 2,8 2,2 2,2 2,2damage Nod 0 0 0,5 0,5 0
damage % 0 0 5 5 0
packing density 0,61 0,56 1,04 1,17 0,70concrete per m2 on slope 0,182Hs 0,148Hs 0,350Hs 0,370Hs 0,236Hs
relative volume of concrete 100% 81% 208% 220% 140%
Reef type (Ahrens): reduction in crest height Conventional structure: emerged, small damage
7/28/2019 47948988 04 Breakwater
106/263
14
Reef type: crest at still water level Reef type: crest below still water level
Reef type: smaller material Reef type: wide crest
Conventional low-crested structure Reef type: lowering of the crest
7/28/2019 47948988 04 Breakwater
107/263
15
Conventional low-crested structure; various crest heights Reef type (Ahrens): reduction in crest height
Division of low-crested structure in three parts (Vidal) Low-crested structure: design of front, crest, rear
Conventional breakwater
Stable structure (damage S)
Reliable design formulae
Well-known structure
Various/many gradings (armour, underlayer(s), toe, bedding layer, etc.)
Heavy equipment (concrete units)
Limited size of rock concrete(expensive)
Berm breakwater,original concept
7/28/2019 47948988 04 Breakwater
108/263
16
Berm breakwater
Use ofrock up to Hs = 6 m cheap (?)
Two classes of rock: large and small
Easy construction
Not many in the world: around 30 (25 on Iceland)
Initially unstable: profile reshaping. After
reshaping statically stable.
Design parameter: mound of berm
Erosion gives gentle and stable slope
Dynamic stability: S-shaped profile independent of
ininital profile
Schematised profile: BREAKWAT
Three curves with BREAKWAT
Basic design parameters
Hs/Dn50 = 3.0
Determine berm level
Draw slope 1:4
Redesign to berm profile
Use BREAKWAT to determine berm
length
7/28/2019 47948988 04 Breakwater
109/263
17
Crest height: rear side stability
Rear side stability is very important for berm
breakwaters: unstable rear side may cause
failure of the breakwater
Consider developed profile
Rc/Hs * sop1/3 = 0.25: start of damage
0.21: moderate damage
0.17: severe damage
A lower value gives more overtopping
Erosion of berm breakwater head
Head, St. George, Alaska. 3D tests
Longshore transport
Longshore transport during reshaping
S(x) = number of rocks displaced per wave
Maximum between 15-40 degrees attack
Ho = Hs/Dn50
Top = Tp/(gDn50)0.5 dimensionless period
S(x) = 0 for HoTop < 105
S(x) = 0.00005 (HoTop- 105)2
Longshore transport: rock/gravel beach; Hs/Dn50 < 8 Longshore transport: onset
7/28/2019 47948988 04 Breakwater
110/263
18
Stable Berm Breakwaters,Sigurdur SigurdarsonIcelandic Maritime Administration
Stability test of the Icelandic type,Juhl and Sloth (EU-programme)
Some of the profiles tested
Conventional
Stability test of the Icelandic type,
Juhl and Sloth
conventional
Husavik berm breakwater, 2001-2002
Stone Classes and Quarry Yield Prediction.
Stone wmin-wmax wmean wmax/ dmax/ Expected For Hs=6.8 m
class (tonnes) (tonnes) wmin dmin quarry yield Ho HoTo
I 16.030.0 20,7 1.9 1.23 5% 1.9 46II 10.016.0 12.0 1.6 1.17 5% 2.3 62
III 4.0 10.0 6.0 2.5 1.36 9% 2.9 87
IV 1.0 4.0 2.0 4.0 1.59 14% 4.2 151
V 0.3 1.0 0.5 3.3 1.49 12% 6.5 291
Grindavik berm breakwaters, 2001-2002
Stone Classes and Quarry Yield Prediction.
Stone wmin-wmax wmean wmax/ dmax/ Expected For Hs=4.4 m
class (tonnes) (tonnes) wmin dmin quarry yield Ho HoTo
I 15.030.0 20,0 2.0 1.26 5%
II 6.015.0 9.0 2.5 1.36 9% 1.7 47III 1.5 6.0 6.0 4.0 1.59 17% 2.4 80
IV 0.3 1.5 2.0 5.0 1.71 20% 3.9 166
Sirevg berm breakwater, NorwayDesign by Icelandic Maritime Administration
7/28/2019 47948988 04 Breakwater
111/263
19
Sirevg berm breakwater, Norway
Design wave height and worst casescenario
Station number
along thebreakwater (m)
Design wave
height 100 yearreturn period
Worst case
scenario 1000year return period
Hs (m) Hs (m)
0 to 70 4.8 5.3
75 to 125 3.5 3.9
145 to 210 6.2 6.8
215 to 240 6.4 7.3
245 to 275 6.2 6.8
280 to 400 6.7 7.4
Breakwater head 7.0 7.7
Sirevg berm breakwater, Norway
Quarry Yield PredictionSIREVG - QUARRY YIELD PRE DICTION
0
10
20
30
40
50
60
70
80
90
100
0,10 1,00 10,00 100,00
Weightof s tones (tonnes)
Quarry A: Yieldprediction
Quarry B: Yieldprediction
Quarries A, B, andC -weighed averages: Yieldprediction
DesignCurve
Sirevg berm breakwater, Norway
Stability number, Ho, for various design
wave heights, Hs
Stone wmin - wmean dmax/ Ho for various Hs
class wmax dmin 3.5 m 4.8 m 6.2 m 6.7 m 7.0 m
I 20 - 30 23.3 1.14 1.05 1.45 1.87 2.02 2.11II 10 - 20 13.3 1.26 1.27 1.74 2.25 2.43 2.54
III 4 - 10 6.0 1.36 1.66 2.27 2.94 3.17 3.31
IV 1 - 4 2.0 1.59 2.39 3.28 4.23 4.57 4.78
Stable berm breakwaters,concluding remarks (Sigurdarson)
18 year experience
27 structures have been built
Design wave 2.5 to 7.0 m
Constructed on 25 m water depth
Breaking waves / non breaking
On weak soil with large settlements
More economical and more stable than the
homogeneous berm breakwater
Toe stability Different toe heights
7/28/2019 47948988 04 Breakwater
112/263
20
Different toe widths Damage definition Nod
Toe stability: old results Toe stability: new results
Hs/Dn50 * Nod-0.15 = 2 + 6.2 (h t/h)
2.7
Application area;
0.4 < ht/h < 0.9
3 < ht/Dn50 < 25
Toe stability: final results (Infram publication nr 2) Damage location head (Jensen, 1984)
7/28/2019 47948988 04 Breakwater
113/263
21
Head stability
No good formulae, too many parameters
Rules of thumb:
increase weight by 50% to 100%
decrease slope angle
increase radius of head
or a combination
3D-tests for important breakwaters
Videos
Scheveningen: land based construction
Maasvlakte: construction from water
Reina Sofia: caisson
7/28/2019 47948988 04 Breakwater
114/263
7/28/2019 47948988 04 Breakwater
115/263
7/28/2019 47948988 04 Breakwater
116/263
7/28/2019 47948988 04 Breakwater
117/263
7/28/2019 47948988 04 Breakwater
118/263
7/28/2019 47948988 04 Breakwater
119/263
7/28/2019 47948988 04 Breakwater
120/263
7/28/2019 47948988 04 Breakwater
121/263
7/28/2019 47948988 04 Breakwater
122/263
7/28/2019 47948988 04 Breakwater
123/263
7/28/2019 47948988 04 Breakwater
124/263
7/28/2019 47948988 04 Breakwater
125/263
7/28/2019 47948988 04 Breakwater
126/263
7/28/2019 47948988 04 Breakwater
127/263
7/28/2019 47948988 04 Breakwater
128/263
7/28/2019 47948988 04 Breakwater
129/263
7/28/2019 47948988 04 Breakwater
130/263
7/28/2019 47948988 04 Breakwater
131/263
7/28/2019 47948988 04 Breakwater
132/263
7/28/2019 47948988 04 Breakwater
133/263
7/28/2019 47948988 04 Breakwater
134/263
7/28/2019 47948988 04 Breakwater
135/263
7/28/2019 47948988 04 Breakwater
136/263
7/28/2019 47948988 04 Breakwater
137/263
7/28/2019 47948988 04 Breakwater
138/263
7/28/2019 47948988 04 Breakwater
139/263
7/28/2019 47948988 04 Breakwater
140/263
7/28/2019 47948988 04 Breakwater
141/263
7/28/2019 47948988 04 Breakwater
142/263
7/28/2019 47948988 04 Breakwater
143/263
7/28/2019 47948988 04 Breakwater
144/263
7/28/2019 47948988 04 Breakwater
145/263
7/28/2019 47948988 04 Breakwater
146/263
7/28/2019 47948988 04 Breakwater
147/263
7/28/2019 47948988 04 Breakwater
148/263
7/28/2019 47948988 04 Breakwater
149/263
7/28/2019 47948988 04 Breakwater
150/263
7/28/2019 47948988 04 Breakwater
151/263
7/28/2019 47948988 04 Breakwater
152/263
7/28/2019 47948988 04 Breakwater
153/263
7/28/2019 47948988 04 Breakwater
154/263
7/28/2019 47948988 04 Breakwater
155/263
7/28/2019 47948988 04 Breakwater
156/263
7/28/2019 47948988 04 Breakwater
157/263
7/28/2019 47948988 04 Breakwater
158/263
7/28/2019 47948988 04 Breakwater
159/263
7/28/2019 47948988 04 Breakwater
160/263
7/28/2019 47948988 04 Breakwater
161/263
7/28/2019 47948988 04 Breakwater
162/263
7/28/2019 47948988 04 Breakwater
163/263
7/28/2019 47948988 04 Breakwater
164/263
7/28/2019 47948988 04 Breakwater
165/263
7/28/2019 47948988 04 Breakwater
166/263
7/28/2019 47948988 04 Breakwater
167/263
7/28/2019 47948988 04 Breakwater
168/263
7/28/2019 47948988 04 Breakwater
169/263
7/28/2019 47948988 04 Breakwater
170/263
7/28/2019 47948988 04 Breakwater
171/263
7/28/2019 47948988 04 Breakwater
172/263
7/28/2019 47948988 04 Breakwater
173/263
7/28/2019 47948988 04 Breakwater
174/263
7/28/2019 47948988 04 Breakwater
175/263
7/28/2019 47948988 04 Breakwater
176/263
7/28/2019 47948988 04 Breakwater
177/263
7/28/2019 47948988 04 Breakwater
178/263
7/28/2019 47948988 04 Breakwater
179/263
7/28/2019 47948988 04 Breakwater
180/263
7/28/2019 47948988 04 Breakwater
181/263
7/28/2019 47948988 04 Breakwater
182/263
7/28/2019 47948988 04 Breakwater
183/263
7/28/2019 47948988 04 Breakwater
184/263
7/28/2019 47948988 04 Breakwater
185/263
7/28/2019 47948988 04 Breakwater
186/263
7/28/2019 47948988 04 Breakwater
187/263
7/28/2019 47948988 04 Breakwater
188/263
7/28/2019 47948988 04 Breakwater
189/263
7/28/2019 47948988 04 Breakwater
190/263
7/28/2019 47948988 04 Breakwater
191/263
7/28/2019 47948988 04 Breakwater
192/263
7/28/2019 47948988 04 Breakwater
193/263
7/28/2019 47948988 04 Breakwater
194/263
7/28/2019 47948988 04 Breakwater
195/263
7/28/2019 47948988 04 Breakwater
196/263
7/28/2019 47948988 04 Breakwater
197/263
7/28/2019 47948988 04 Breakwater
198/263
7/28/2019 47948988 04 Breakwater
199/263
7/28/2019 47948988 04 Breakwater
200/263
7/28/2019 47948988 04 Breakwater
201/263
7/28/2019 47948988 04 Breakwater
202/263
7/28/2019 47948988 04 Breakwater
203/263
7/28/2019 47948988 04 Breakwater
204/263
7/28/2019 47948988 04 Breakwater
205/263
7/28/2019 47948988 04 Breakwater
206/263
7/28/2019 47948988 04 Breakwater
207/263
7/28/2019 47948988 04 Breakwater
208/263
7/28/2019 47948988 04 Breakwater
209/263
7/28/2019 47948988 04 Breakwater
210/263
7/28/2019 47948988 04 Breakwater
211/263
7/28/2019 47948988 04 Breakwater
212/263
7/28/2019 47948988 04 Breakwater
213/263
7/28/2019 47948988 04 Breakwater
214/263
7/28/2019 47948988 04 Breakwater
215/263
7/28/2019 47948988 04 Breakwater
216/263
7/28/2019 47948988 04 Breakwater
217/263
7/28/2019 47948988 04 Breakwater
218/263
7/28/2019 47948988 04 Breakwater
219/263
7/28/2019 47948988 04 Breakwater
220/263
7/28/2019 47948988 04 Breakwater
221/263
7/28/2019 47948988 04 Breakwater
222/263
7/28/2019 47948988 04 Breakwater
223/263
7/28/2019 47948988 04 Breakwater
224/263
7/28/2019 47948988 04 Breakwater
225/263
7/28/2019 47948988 04 Breakwater
226/263
7/28/2019 47948988 04 Breakwater
227/263
7/28/2019 47948988 04 Breakwater
228/263
7/28/2019 47948988 04 Breakwater
229/263
7/28/2019 47948988 04 Breakwater
230/263
7/28/2019 47948988 04 Breakwater
231/263
7/28/2019 47948988 04 Breakwater
232/263
7/28/2019 47948988 04 Breakwater
233/263
7/28/2019 47948988 04 Breakwater
234/263
7/28/2019 47948988 04 Breakwater
235/263
7/28/2019 47948988 04 Breakwater
236/263
7/28/2019 47948988 04 Breakwater
237/263
7/28/2019 47948988 04 Breakwater
238/263
7/28/2019 47948988 04 Breakwater
239/263
7/28/2019 47948988 04 Breakwater
240/263
7/28/2019 47948988 04 Breakwater
241/263
7/28/2019 47948988 04 Breakwater
242/263
7/28/2019 47948988 04 Breakwater
243/263
7/28/2019 47948988 04 Breakwater
244/263
7/28/2019 47948988 04 Breakwater
245/263
7/28/2019 47948988 04 Breakwater
246/263
7/28/2019 47948988 04 Breakwater
247/263
7/28/2019 47948988 04 Breakwater
248/263
7/28/2019 47948988 04 Breakwater
249/263
7/28/2019 47948988 04 Breakwater
250/263
7/28/2019 47948988 04 Breakwater
251/263
7/28/2019 47948988 04 Breakwater
252/263
7/28/2019 47948988 04 Breakwater
253/263
7/28/2019 47948988 04 Breakwater
254/263
7/28/2019 47948988 04 Breakwater
255/263
7/28/2019 47948988 04 Breakwater
256/263
7/28/2019 47948988 04 Breakwater
257/263
7/28/2019 47948988 04 Breakwater
258/263
7/28/2019 47948988 04 Breakwater
259/263
7/28/2019 47948988 04 Breakwater
260/263
7/28/2019 47948988 04 Breakwater
261/263
7/28/2019 47948988 04 Breakwater
262/263
7/28/2019 47948988 04 Breakwater
263/263