【正文】 f = 100 Kpa, vacuum prepression pound with loading method. The hydraulic filling of sea sand should be adopted under the elevation +, which is specified in the tender documents. But based on our site investigation report, we propose to use sweet water sand instead of sea sand for these following reasons: Proposed Design Philosophy, Construction, Installation and Monitoring Method As per of Section of ITB 2 2 (1) Fine grade and high mud content of the sea sand。 (2) No local facilities available such as hydraulic filling mud absorption. The backfill material (sweet water sand) will be delivered by barges to the nearest dock and then carried by trucks to the site. Monitoring devices According to the requirement of the tender documents, settlement gauge should be installed at 50mx50m grid and be measured by leveling instruments. In accordance with the requirement of the owner, the static peration test should be carried out at the 10 specified points and the peration instruments should be buried through the whole depth of the pressible soil layers. The paction test of filling materials in site should be carried out with heavy pactor. 4. Design philosophy to achieve the requirement of the specification for soil improvement philosophy of vacuum prepression method The vacuum prepression method is used to consolidate foundation soil. This method consists in laying on the surface of foundation soil a sand bed, and in installing a drainage system with wick drains. The sand bed drain line is buried and connected with vacuum system to form an air exhaust and a dewatering system. A set of airtight seal membranes is laid on the surface of the sand bed with its edge buried in soil. Thus, a negative pressure area within sand bed and foundation soil can be formed from air exhaust and dewaturing pumps. The vacuum method can reach a soil bearing capacity of 80KPa. Under the vacuum condition, soil is in the state of consolidating and pore water is discharged from soil under the pressure difference. The consolidation is pleted when pressure of soil to be consolidated is reaching the same pressure of the drainage system. The philosophy of vacuum repression method is that under the pressure difference (PaPv), soil can be consolidated。 f = 75 Kpa, vacuum prepression and filling water () on membrane method。 Pa indicates atmospheric pressure and Pv indicates air pressure in the sand bed and the vertical drains. In the calculation of consolidation of the foundation soil, the RENDULICTERZAGE Theory and BICOT Theory of Consolidation can be adopted which are the same of those adopted in loading repression method. The drop of the ground water table may also accelerate the consolidation of foundation soil beside the pressure difference. The effective stress in the soil increases successively during the period of Proposed Design Philosophy, Construction, Installation and Monitoring Method As per of Section of ITB 3 3 consolidation of the foundation soil with vacuum repression method. The horizontal displacement of the soil is toward the center of the consolidation area from the beginning of the period of vacuum repression, which is different from