FEM analysis of vertical soil deformation caused by vacuum pumping

When deep and thick soft ground is improved by vacuum preloading, lateral contract deformations will be induced in the soils, and this is beneficial to ground stability. On the other hand, the lateral deformation towards the vacuum preloading area will have an adverse effect on the adjacent buildings, underground pipelines, road embankments and other structures. Serious engineering failures may take place, such as crack of the pipelines, collapse of the retaining walls, and damage of the road embankments. In order to investigate the impact of the vacuum preloading on the surrounding soils, FEM analysis has been carried out, considering the influence of soils' tension crack. The variation behavior during the vacuum preloading process is studied on the settlement at different depths and at different distances away from the preloading area. It has been found that the calculation results from the FEM analysis based on the Biot's theory and the consideration of tension crack are consistent with the measurement results of the settlements and the extents of the influence outside the preloading area.