PORT WORKS DESIGN MANUAL PART 3 Guide To - The University ...

2!verification of stability by calculation is required.Normally, end tipping canbe carried out in two stages, firstly to a general level just above the high watermark and later to the formation level of the reclamation.• Sampans should be employed to pick up floating material from the water withinthe reclamation site.Such material is unsightly and can be hazardous toshipping if allowed to drift into open waters. Floating refuse containmentbooms should be used to surround the site to contain the debris and to facilitateremoval by the sampans.2.7.3 Marine FillThe use of marine sand fill can be economically viable for a reclamation project where amarine borrow area is within a reasonable distance of the site and where the size of theproject justifies the use of sophisticated dredgers, which have high mobilization costs.Plantsuch as trailing suction hopper dredgers may dredge marine sand fill at relatively low costs,depending on the thickness of the overburden at the marine borrow area.The rate offormation of reclamation can be very rapid compared to the use of other types of fill, andoften several dredgers can be used on the same site, if necessary.These dredgers candeposit marine sand in the reclamation by bottom dumping or by pumping, depending on theaccess and water depth available.The maximum fines content (smaller than 63 pm) of the marine fill used in reclamationshould always be less than 30% but for hydraulically placed fill, it is usually limited to about10%. The specification should suit the reclamation design. If the marine sand is to bedensified by vibrocompaction, the maximum fines content requirement will need to be morestringent (see Figure 3). This requirement applies to fill as delivered to the reclamation site,and not necessarily to in-situ material in the borrow area.Sampling on-board dredgers tocheck the grading of material is one method to confirm that the required specification for filldelivered to the site is satisfied. Samples can also be taken at the reclamation site, to checkif segregation of material has occurred during placing, with a view to ensuring that the finesare well distributed within the reclamation.For proper control of the works on site, the testsfor the suitability of marine fill and the uniformity of the as-placed material should be statedin the specification.2.1 A Crushed RockCrushed rock from local land sources should not normally be used for reclamation in view of