ABSTRACT
There are three typical deformation models of element soil under vacuum load: the three-dimensional equal strain model, lateral limit deformation model, and axisymmetric deformation model. Only when the initial effective stress of soil is greater than the critical initial effective stress, the deformation of element soil is close to the model of lateral limit deformation, and the critical initial effective stress increases with the vacuum load. In addition, the effective internal friction angle decreases with the increase of the over consolidation ratio. For the undisturbed silt, the deformation law of a single shaft is close to the lateral limit deformation model. For dredger fill, the soil around the vertical drainage body produces equal axial strain and radial strain, thus forming a “soil column,” and the “soil column” can be slowed down by step loading. The lateral deformation depth of soil at the boundary of the reinforcement zone is calculated and analyzed. A formula for calculating the lateral deformation of vacuum preloading is given. The formula has been applied in practical engineering, and the calculated results are close to the measured values.
