Consolidation Analysis of Soft Soil by Vacuum Preloading Considering Groundwater Table Change

Vacuum preloading is a commonly-used method to improve a large area consisting of soft soil. However, most theoretical and experimental studies have not considered the water table charge during vacuum preloading. This paper analyzed the changes of excess pore water pressure and groundwater table during the process of vacuum preloading, and confirmed that the groundwater table varied during vacuum preloading and had influence on the consolidation process. Based on the field observation, an analytical solution to calculate the consolidation degree of soil by vacuum preloading considering the groundwater table change was developed. Then a parametric study was conducted to investigate the influence factors of the drain spacing ratio, depth of ground water level, soil permeability coefficient ratio of undisturbed area and disturbed area on the consolidation. The developed solution is valuable for the prediction of consolidation degree under vacuum preloading in practice.