TRIANGULAR SPACING-FT.
15
5 4 3 2 - 0
14
13
FIG. 4: SURCHARGE / SAND-DRAIN SPACING
60% CONSOLIDATION
5 YEARS-
80% CONSOLIDATION
60% CONSOLIDATION
2 YEARS
9
8
80% CONSOLIDATION
7
6
10
SURCHARGE FT. OF FILL
20
Recommended Methods
10.30 The arguments advanced in the previous Sections of this Chapter lead to the conclusion
that in order to bring reclamation into early effective use either:-
(a) Some of the very soft clay existing below the seabed should be removed, or (b) Sand or paper drains should be installed after the reclamation is completed.
10.31 The installation of sand or paper drains would be hindered by the presence of rock in filling material. Also, behind the existing breakwater it will be necessary to pile for the foundations of the proposed mass-transport railway and possibly for the packing-shed foundations. On the other hand, rock is usually available for dumping from site-formation projects and its presence in the fill would help to limit settlement. With the proposed layout for the Container Terminal, it is not envisaged that piling would be required between the existing breakwater and the proposed quaywall. This area is planned for container- marshalling operations, which are considered to be the most sensitive to settlement. It is recommended therefore that in front of the existing breakwater and Mong Chau, some of the existing soft clay should be dredged out before filling commences and that rock
44