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Unformatted text preview: on increase the risk of stone degradation and breakage;
• Loss of larger armour stone to lower slope represents a waste.
Two additional tests were undertaken with refined cross-sections, with
various modifications made to reduce stone motion and profile development,
• Reduced slope on upper berm;
• Tighter placement of armour stone above water level;
In addition, various transition details were tested between the “root” of the
breakwater (located in the shelter of Pointe Ehoala) and the full cross-section.
The final test included detailed documentation of breakwater profile
development throughout two design events, as well as extended test durations
following the storm peak to assess residual stone motion. In addition,
sensitivity tests were undertaken to assess the impact on stability of smaller (1015 t) or larger (18-25 t) stone in the primary berm. Figure 10 presents profile
measurements collected during the final test series; these results demonstrate the
limited profile development that occurred in the final test. 11 15 10 5 0 -5 -10 Design profile
4 hours -15 6 hours
Core profile -20
0 5 10 15 20 25 30 35 40 45 50 55 60 65 Figure 10 – Profile Measurements During Final Test of Full Cross-Section Figure 11 illustrates the final design cross-section, as tested in the physical
model (the dark area is the interim armour layer). Relative to the preliminary
design (refer to Figure 7), the final design is more efficient, providing better
performance (i.e. reduced stone motion and profile development) with a smaller
total volume of stone, and a reduced proportion of the largest stone class. Figure 11 – Final Design Cross-Section for Breakwater BIDDING AND CONSTRUCTION The Port d’Ehoala project was bid using the World Bank’s two stage
process. Five contractors were pre-qualified and submitted Initial Technical
Proposals (ITPs) in June 2006. As expected, the five ITPs included varied
construction approaches and equipment, and several different structural
concepts for the...
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This note was uploaded on 02/04/2014 for the course HE 8450 taught by Professor Verhagen during the Spring '14 term at Technische Universiteit Delft.
- Spring '14