Enayam Port

Tamil Research Institute
RAPID TECHNO-ECONOMIC FEASIBILITY REPORT FOR
DEVELOPMENT OF COLACHEL PORT AT TAMILNADU
FINAL REPORT
4.3. RUBBLE MOUND FOUNDATION
Toe protection to caisson or vertical wall breakwaters
The presence of vertical structures leads to an amplification of near-bed water particle velocities, due to
wave reflection. Design of a rubble protection in front of such a structure therefore requires lower toe
stability numbers Ns = Hs/(ΔDn50) than needed for a sloping rubble face.
4.4. TOE PROTECTION:
N
s
H
D
s
n50
h
h
b
0.19
5.8
0.6 Nod
s
1
w
h b =depth of the top of the toe protection
h s = depth of the bottom of the toe protection
The values of the damage number, Nod, to be used are as follows:
N od
0.5
2
5
almost no damage
acceptable damage
failure
3
Hs
W
N
s
CP1832-FR-AX-04-CP-Breakwater-Design.Ed1.docx AX04 - 14
www.tamilri.com