To exemplify the contrasting reclamation approaches in deep and shallow water regions, consider the following scenarios:
Deep Water Reclamation:
- Initial seabed level: -8.5mPD
- Geotextile and 1.5m sand blanket placement: Top level at -7mPD
- Split barge dumping of public fill: Up to -2.5mPD
- End dipping by trucks: From -2.5mPD to +2.5mPD (final reclamation level)
In this scenario, split barges handle initial fill placement due to the depth. However, as the fill reaches -2.5mPD, the water becomes too shallow for barge access. Thus, end dipping by trucks is employed for the final phase.
Shallow Water Reclamation:
- Initial seabed level: -5.5mPD
- Geotextile and 1.5m sand blanket placement: Top level at -4mPD
- Split barge dumping: Up to -2.5mPD
- Half-loaded derrick barge dumping: From -2.5mPD to 0mPD
- End dipping by trucks: From 0mPD to +2.5mPD
Here, split barges are initially used, but due to the shallower starting depth, the fill layer above the seabed remains relatively thin (-2.5mPD). End dipping at this stage would risk mud wave formation, thus half-loaded derrick barges are utilized to reach 0mPD, establishing a thicker fill layer. Beyond this, end dipping is safe for the final phase.
These examples showcase the distinct considerations for reclamation in different water depths. In deep water, the focus is on transitioning from barge to truck filling as depth decreases. In shallow water, the priority shifts to preventing mud waves by strategically increasing fill thickness before employing end dipping. The specific reclamation sequence is adaptable, but these examples highlight the importance of tailoring the approach to the unique challenges posed by each environment.