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would be easier to dredge. Further, a berth aligned along the aeolianite/beach
rock feature would be parallel to the predominant wind direction, a benefit with
respect to the departure of fully laden ships. These factors, among others, led to
the development of the port layout shown earlier in Figure 2.
The uncertainty related to the subsurface conditions (i.e. due to the absence
of geotechnical information) was a key uncertainty/risk for the design of the
quay structure. This issue was addressed as follows:
• Quay to be bid as a design-build component;
• Assumed soil conditions presented in Bid Documents:
• Contractor to do geotechnical investigation as early stage of work;
• Contractor to develop final design for quay structure;
• Baird to review and approve final design;
• Negotiation to address cost implications of change in soil conditions.
This approach was deemed to be the best way to address the
uncertainty/risk noted above, and also allowed individual Bidders to propose
different design concepts that take advantage of their varied project experience
In addition, there was some uncertainty regarding the sediment transport
processes in the bay, due to the complex (bi-modal) wave climate and the lack
of historical information on shoreline variability. As such, a groyne was
incorporated in the project design (north of the dredged harbour basin), with the
length of the groyne to be established by beach monitoring during construction.
DESIGN CONDITIONS The wave climate at this site is characterized by persistent southerly swells
(Hs = 2 to 3 m is typical), with intermittent easterly seas. In addition, the region
is subject to the effects of tropical cyclones, with the potential for very severe
wave conditions, though such events are rare (the last one being a “near miss”
by Deborah in 1975). The tidal range is relatively small (less than 1 m).
Extensive wave climate investigations were undertaken to define the wave
climate at the site. A long-term hindcast (1985-2004) was undertaken for the 5 entire Indian Ocean in order to simulate the generation and propagation of
swells (generated b...
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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