Theoretical solution for consolidation of composite foundations considering construction disturbance and loading effect

Under the condition of equal strain,using a new initial condition derived from equilibrium equations and equal strain assumption,and considering the gradual variation of horizontal permeability of disturbed soils and the change of the total stress with depth in composite foundations,the excess hydrostatic pressures in the column and the surrounding soil were obtained and the overall average consolidation rates defined in terms of stress and deformation were given.Finally,the influences of several factors,such as the distribution of the total stress in composite foundation,the size of disturbed zone and the variation of the horizontal permeability of soils on the consolidation of composite foundation were analyzed.The results showed that the solution of overall average consolidation rate in terms of stress was equal to that in terms of deformation;the consolidation of composite foundations was accelerated with the increase in the ratio of top total stresses to the bottom total stress in the composite foundation;the consolidation rate was at its maximum when the total stress distributes in the form of a triangle and at its minimum when the total stress distributes in the form of a reversed-triangle;the larger the smeared zone was or the faster the horizontal permeability of soils decreases with radial distance away from column,the slower the consolidation rate was.