Enayam Port

Tamil Research Institute
RAPID TECHNO-ECONOMIC FEASIBILITY REPORT FOR
DEVELOPMENT OF COLACHEL PORT AT TAMILNADU
FINAL REPORT
3. RUBBLE-MOUND BREAKWATER
3.1. ARMOR LAYER
It has been considered accropodes for the armour units and near de coastal line in shallow water cubic
blocks have been considered for the armour units.(around the depth of -5m).
Hudson formula have been used for calculating the weight of armour unit:
Where:
=Mass density of Armour units
H=Design Wave Height
K D =Stability Coefficient
=
=Mass density of Water
cot α=Armour Slope (H/V)
Hudson formula for randomly placed concrete armour units has been rewritten as presented in the next
equation, it has been taken from CIRIA
Using the significant wave height, Hs(m) and the nominal diameter of the unit, Dn (m).
The values of the Stability Coefficient for Accropodes is K D =15 in the Trunk of the breakwater portion
and for cubic blocks is K D =6
Van der Meer formulas have been also considered for the design of the armour layer , these formulas are
especial for accropodes: (CIRIA)
For the Rubble-mound breakwater design it has been taken three parts depending on the wave height:
• First Section :It is the deepest part of the rubble-mound breakwater ( around the depth of -15 m
to -11m ),the wave height has been taken from the point of interest (P3 and P2), Hs= 5 m
CP1832-FR-AX-04-CP-Breakwater-Design.Ed1.docx AX04 - 5
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