Abstract:In order to get the settlement development pattern of vertical sand foundation under vacuum-surcharge preloading, A analytical solution was obtained for the consolidation of vertical sand foundation, under vacuum preloading considering, the vacuum degree was linearly changed along the vertical drain depth, the loading was applied in a single-stage way, both horizontal and vertical drainage, and the parabolic distribution pattern of horizontal permeability coefficient of soil was considered. Furthermore, the consolidation behavior of vertical drain foundation was analyzed. The results show that the loading is applied gradually, the larger the vacuum is, the faster the consolidation is, the slower the reducing of vacuum is, the faster the consolidation. Ignoring the vertical flow within the soil will under-estimate the consolidation rate. Furthermore, the less the radius ratio is, and the less the ratio of horizontal permeability to vertical permeability is, the greater the under-estimated value is.