Consolidation analysis and effect analysis in the treatment of soft foundation by vacuum preloading

Abstract

Vacuum preloading is a common method in the treatment of soft soil foundation. Combined with field test engineering cases, the plastic drainage board is equivalently processed into sand well units. The analytical solution of the sand well consolidation equation under the linear attenuation of vacuum preloading is derived to evaluate the consolidation degree of the site. The results showed that the vacuum negative pressure reached -85 kPa at 20 d, and the pore water pressure in the silt soil continued to dissipate to produce negative pore pressure, and finally reached a stable value at 60 d. Considering that the vacuum negative pressure affects the change of pore pressure, it is concluded that the vacuum negative pressure attenuates 3.4 kPa/m along the depth of the soil. Based on the data obtained on site, the solution in this paper is compared with the Hansbo solution, which is closer to the actual project.