RETRACTED: Mechanism analysis on ground settlement induced by vacuum removal (Retracted Article)

Due to the settlement hazards induced by the soft clayey soils, vacuum preloading has been widely used all over the world. Many studies focus on the process of vacuum application but the process of vacuum removal is generally ignored. Different from observations on surcharge preloading, ground settlement rather than heave occurred during vacuum removal. In this study, a stress-controlled triaxial test was carried out to simulate both processes of vacuum application and removal applied on a clayey soil and hence the mechanism of ground settlement induced by vacuum removal is discussed. Compressive axial strain was observed during the decrease of isotropic stress that simulated vacuum removal. To better understand the observed deformation characteristics of the clayey soils during vacuum removal, in this study, a simple anisotropic elastic model was used. The happening of ground settlement of the clayey soil during vacuum removal is mainly because that the Young's modulus in the vertical direction is higher than that in the horizontal direction. Lateral extension is dominant for the ground deformation during vacuum removal.