【正文】 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。 Proposed Design Philosophy, Construction, Installation and Monitoring Method As per of Section of ITB 1 1 Proposed Design Philosophy, Construction, Installation and Monitoring Method ( as per of section ) 1. Source of borrows pit indicating the location and quantity We have license given by Vietnam authority to exploit a quantity of 8, 400,000 m3 in Nha Be river and the location is in Nhon Trach district, Dong Nai province. 2. Physical proprieties of proposed fill material The sampling test of sand proposed to use is carried out according to AASHTO M4589, C14488 (see Test Result of Analyses of Sand ponent). The specific weight of the sand is , unit weight , organic content % and modules . 3. Proposed method of statement and monitoring devices Method statement According to the geotechnical report of the site, the void ratio of the soft silty clay (e) is , and the permeability coefficient (Kv) *107cm/s. If we adopt “wick drains and preloading” method to reach a soil bearing capacity of 50Kpa, 75Kpa, 100Kpa under the site’s conditions, the consolidation period wo uld be far beyond the proposed work period. For the purpose of reducing the consolidation period of foundation soil an overload should be added, though the loading would be high to fulfill the bearing capacity of 100Kpa. Obviously, this technique would bear a tremendous number of loading and unloading, which would also mean a high construction cost. The stability of side slope would also be difficult to monitor. Based on our previous experience of soft soil improvement of China coastal and Hiep Phuoc Power Plant in Nha Be, 15km Southeast of Hochiminh City, the preloading method is appropriate only for general area. In process area we suggest to adopted the following method (details see drawings “ Proposed Process Area Plan” and “ Proposed Process Area Zone” in page 6, 7): f = 50 Kpa, vacuum prepression method。 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 s