Chapter IV
Design of rubble mounds breakwater
60
The application of Van der Meer's formula provides a higher level of stability against wave
actions compared to the results obtained with Hudson's formula. For instance, in the Khireddine
jetty, the average block mass for current section armor layer calculated using Hudson's formula
is 11.4 t, while Van der Meer's formula yields a significantly higher value of 20 t. Furthermore, it
is important to highlight that the obtained results are consistent with those obtained in the
previous chapter, where the weight of the blocks constituting Khireddine jetty is higher than that
of the blocks constituting the main jetty of Marina. This is due to the fact that Marina is naturally
protected against wave impacts.
In summary, the calculations using Van der Meer's formula indicate a higher level of stability
and require larger block masses compared to those obtained with Hudson's formula. These
results demonstrate the importance of considering additional variables in the design process,
especially for critical structures like breakwaters.
Table IV-10 Summary of Calculations for the Design of Marina's Main Jetty.
Block type
Naturel rock
Cubipod
Part in the main jetty
Trunk
Current
section
Roundhead
Design Wave (m)
2.34
5
Formula used
Hudson Van Der Meer
Hudson
Armor
Layer
Average Block Mass (t)
1.6
3.6
2.9
11.96
Layer Thickness (m)
1.9
2.6
2.37
3,76
underlayer
Average Block Mass (t)
0.16
0.36
0.29
1.2
Layer Thickness (m)
0.9
1.18
1.11
1.76
Core
Weight of TVC materials
(t)
< 0.1
Toe bund
Average Block Mass (t)
1.81
Thickness and Length (m)
2.03
Table IV-11 Summary of Calculations for the Main Jetty Design at Khireddine Port in Algiers.
Block type
Parallelepiped
Grooved cube (antifer type)
Part in the main jetty
Trunk
Current section
Roundhead
Design Wave (m)
3.82
4.88
5.9
Formula used
Hudson
Van
Der
Meer
Hudson
Van
Der
Meer
Hudson
Van
Der
Meer
Armor
Layer
Average Block Mass (t)
4.7
9.7
11.4
20
27.5
35
Layer Thickness (m)
2.75
3.5
3.86
4.31
4.96
5.2
underlayer
Average Block Mass (t)
0.47
0.97
0.114
2
2.75
3.5
Layer Thickness (m)
1.29
1.64
1.74
2.09
2.33
2.52
Core
Weight of TVC materials
(t)
< 0.1
Toe bund
Average Block Mass (t)
6.3
Thickness and Length
(m)
3
Design of rubble mounds breakwater
60
The application of Van der Meer's formula provides a higher level of stability against wave
actions compared to the results obtained with Hudson's formula. For instance, in the Khireddine
jetty, the average block mass for current section armor layer calculated using Hudson's formula
is 11.4 t, while Van der Meer's formula yields a significantly higher value of 20 t. Furthermore, it
is important to highlight that the obtained results are consistent with those obtained in the
previous chapter, where the weight of the blocks constituting Khireddine jetty is higher than that
of the blocks constituting the main jetty of Marina. This is due to the fact that Marina is naturally
protected against wave impacts.
In summary, the calculations using Van der Meer's formula indicate a higher level of stability
and require larger block masses compared to those obtained with Hudson's formula. These
results demonstrate the importance of considering additional variables in the design process,
especially for critical structures like breakwaters.
Table IV-10 Summary of Calculations for the Design of Marina's Main Jetty.
Block type
Naturel rock
Cubipod
Part in the main jetty
Trunk
Current
section
Roundhead
Design Wave (m)
2.34
5
Formula used
Hudson Van Der Meer
Hudson
Armor
Layer
Average Block Mass (t)
1.6
3.6
2.9
11.96
Layer Thickness (m)
1.9
2.6
2.37
3,76
underlayer
Average Block Mass (t)
0.16
0.36
0.29
1.2
Layer Thickness (m)
0.9
1.18
1.11
1.76
Core
Weight of TVC materials
(t)
< 0.1
Toe bund
Average Block Mass (t)
1.81
Thickness and Length (m)
2.03
Table IV-11 Summary of Calculations for the Main Jetty Design at Khireddine Port in Algiers.
Block type
Parallelepiped
Grooved cube (antifer type)
Part in the main jetty
Trunk
Current section
Roundhead
Design Wave (m)
3.82
4.88
5.9
Formula used
Hudson
Van
Der
Meer
Hudson
Van
Der
Meer
Hudson
Van
Der
Meer
Armor
Layer
Average Block Mass (t)
4.7
9.7
11.4
20
27.5
35
Layer Thickness (m)
2.75
3.5
3.86
4.31
4.96
5.2
underlayer
Average Block Mass (t)
0.47
0.97
0.114
2
2.75
3.5
Layer Thickness (m)
1.29
1.64
1.74
2.09
2.33
2.52
Core
Weight of TVC materials
(t)
< 0.1
Toe bund
Average Block Mass (t)
6.3
Thickness and Length
(m)
3