【文章內容簡介】 can be increased to (Pp – PV) and the consolidation effect would be improved as a result. The process of vacuum pound with preloading method is shown in drawing “ The Process drawing of Vacuum Prepression bined with Loading Method” in page 10. Monitoring method The loading height and loading period of each step of general area is mainly controlled by the stability of the foundation soil. The settlement monitoring should be mainly concerned in this area. Because the vacuum prepression method will not cause a soil stability problem, the site measurements have less significance parable to preloading method. According to the requirement of the tender documents, settlement gauges should be installed at 50mx50m grid and be measured by leveling instruments. The total settlement and settlement speed of the foundation in the loading area as well as the settlement or the rising height in the surrounded area must be monitored. The final settlement S? can be calculated from the site monitoring data. The consolidation settlement Sc and the average consolidation ratio are obtained from this value. Moreover, the ? value can also be calculated as well as the average consolidation coefficient Cv. Proposed Design Philosophy, Construction, Installation and Monitoring Method As per of Section of ITB 4 4 According to 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. Preliminary geotechnical design for vertical drains and soil discharge The type SPB plastic drainage plate is adopted as the vertical drains in this project. The vertical drains would be distributed accordingly to an equilateral triangle pattern. Based on our previous experiences of soft soil improvement in the Mekong delta area and according to the work requirements from the project, we believe that the bearing capacity of processed foundation soil can be reached. However, it is arduous to reach the same requirement for the deformation. It needs a paratively long period to attain a stable state of foundation soil settlement. In accordance with the tender document for the general area, the filling materials have to be well pacted to meet the building standard. Still, there are no relevant requirements of bearing capacity, so the inserting depth of the vertical drains should be less than the thickness of the soft soil layers to avoid the occurrence of extreme settlement. In the opposite case, that would imply a large additional quantity of loading materials and a soaring construction cost. Combining vacuum technique with loading method, the different requirements of bearing capacity of process area can be firmly met. Obviously, the airtight condition during vacuum prepression is a critical factor to ensure a sufficient vacuum level. The depth of vertical drains in the process area is estimated to be 10m to ensure that the end of vertical drains is within the soft soil layer which is about 14m depth. This will avoid any leakage from lower sand layer. The interval of the vertical drains in general area: L = For process area: f =5 t/m2, L = . f = t/m2, L =