Land and Sources of Fill
1.9
A summary of land areas and approximate filling-material requirements for each stage are given in Table 2.
TABLE 2: LAND AREAS & FILLING QUANTITIES
Stages
Formed Area (acres)
Reclamation Area (acres)
Filling Material (million cu.yds.)
Stage 1:
1st Phase
2nd Phase
23
11
28
22
14
Total
51
33333
24
Stage 2
26
23
Stage 3
37
31
24
Totals
114
87
61
1.10
As the source of filling material, four borrow areas are recommended for reservation, two on the Mainland and two on Tsing Yi Island. It is planned that only one of the Tsing Yi borrow areas would be used, with the second in reserve to allow for more extensive reclamation in Stage 3 should this be required or if any of the other areas prove inadequate or not available when required. One of the Mainland areas when formed could be used for industrial development.
Settlement of Reclamation
1.11
One of the most difficult and expensive problems to solve has been that of settlement of the reclamation caused by the very soft clay underlying the site. It is recommended that the proposed Terminal area behind the existing breakwater should be reclaimed with soft material and that to hasten settlement of the underlying clay, 12 in. diameter sand drains with triangular spacing at 7-ft. centres or equivalent should be sunk through it. The Terminal area in front of the existing breakwater should be reclaimed using a mixture of rock and soft material but before this is done, the very soft clay layer should be reduced in thickness to a maximum of 10 ft. by dredging.
1.12 By using these methods it is hoped to minimise settlement of the container-marshalling and packing-station areas after they are brought into use, but some settlement could still take place during the first few years and thus the surfacing must be such that it can be made up when required without waste or excessive cost. To minimise the amount of making up, the reclamation should be formed higher than planned final levels.
Weather Effects
1.13
1.14
The number of days on which operations are likely to be interrupted or slowed down by weather cannot be assessed accurately without extensive observations and model tests. From the limited information available at present it is estimated that on average:-
(a) Container operations anywhere in the Port would have to cease on 6 to 12 days a
year because of typhoons and rain.
(b) Container operations at Kwai Chung would be interrupted for short periods or
slowed down on 7 to 14 days a year because of swell.
It is realised that this forecast could underestimate the problem of surging and for this reason the Hydraulics Research Station now recommends that wave recordings for a full south-west-monsoon season be taken and model tests be carried out. This would enable an assessment to be made of whether the degree of interruption to working would be excessive and if so whether further investigations should be made to attempt to find a remedy.
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