Abstract:

This article presents a design approach for soft soil ground by using prefabricated vertical drains (PDC) in combination with vacuum and surcharge preloading. The method is applied for treatment of soft ground in Long Phu thermal power factory - Soc Trang province. According to the geotechnical survey results at Long Phu thermal power plants - Soc Trang, soft soil thickness is 15 - 18m and has adverse physico-mechanical properties for construction. The settlement prediction of soft ground is from 1.34 to 1.83m, which is higher than the limit, 20cm. For improving the soft ground, the PVD is installed in a square pattern with 1.0x1.0m drain spacing. The vacuum pressure, in average of 70 - 80kPa, is applied continuously from 150 to 170 days until the required degree of consolidation is achieved. The settlement of the forecast is compared to the measurement results in the field. The research results indicate the validation of the proposed method. Therefore, it is possible to apply this calculation method in soft ground by PVD combined with vacuum and surcharge preloading in Vietnam.