Experimental research on hydraulic filled mud consolidated by vacuum preloading method combining long and short boards with thin sand cushions

The vacuum preloading method combining long and short boards with thin sand cushions is a new technology to consolidate newly reclaimed mud foundation. The experimental research indicates that the average soil compression reaches 30%, obviously showing large deformation features, and the average degree of consolidation reaches above 80% after vacuum preloading of 90~120 days. The soil strength significantly increases and the surface bearing capacity reaches 50 kPa or above. This method needs less amount of sand and is convenient for inserting the plate on the surface and improves the surface drainage condition significantly. To this end it can meet the requirements of the construction of shallow rapid reinforcement. The geotextile to protect the membrane can maintain steady vacuum degree under the membrane and benefit drainage consolidation and strength increase. By placing the sand cushions and vertical drainages with long and short boards, the radical flow of soil particles in the newly reclaimed mud foundation with extra high water content under negative pressure can be balanced and controlled, the radical drainage channel congestion in duled by mud gathering around the drainage boards can be avoided, and the uniformity of the consolidation effect is thus ensured. The physical and mechanical properties of the reclaimed mud foundation is significantly improved after consolidation, whose developing trend and orbit are in agreement compared with those of the normal mud soft soil, and the correlation laws of their main indices are consistent in general.