182
Coastal Engineering: Theory and Practice
Table 5.3. Maximum wave conditions during the tests (regular waves).
Armour
slope
Wave
period (s)
Wave
height (m)
Damage
Stability
coefficient (Kp)
% Damage
Type
1 in 1.5
1.2
0.21
0%
none
11*
1.4
0.25
0%
none
19*
1.6
0.3
0.3%
Roll down
32
1.8
0.31
0.8%
Roll down
35
2.0
0.32
0.3%
Roll down
39
1 in 2.0
1.2
0.22
0.7%
rocking
10*
1.4
0.26
0.7%
rocking
16*
1.6
0.31
0.24%
Roll down
27
1.8
0.28
0.24%
Roll down
20
2.0
0.31
0.24%
Roll down
27
1 in 2.5
1.2
0.22
0.37%
rocking
8*
1.4
0.24
0.18%
rocking
10*
1.6
0.32
0.18%
Roll down
23
1.8
0.3
0.18%
Roll down
19*
2.0
0.32
0.55%
Roll down
23
* Limited wave génération capacity, no instability.
Table 5.4. Recommended values of Kjj for KOLOS (non-breaking waves).
Trunk Slope
Hudson’s stability coefficient for trunk (Kp>)
Zéro Damage
Upto 0.5% Damage
1 in 1.5
23
32
1 in 2.0
19.5
27
1 in 2.5
14
23
5.7.1 Damage assessment
General
The total percentage of damage of any breakwater cross-section can be
assessed either by measuring the damaged portion or by counting the number of displaced units. Both the methods are explained below.
Area method
The damage to the armour layer can be given as a percentage of displaced
blocks related to a certain area (the whole or a part of the layer). Damage
can be defined as the relative damage, No, which is the actual number of
units displaced or rocking related to a width along the longitudinal axis of