2D analytical solution of consolidation for vacuum preloading combined with electro-osmosis drainage considering reduction of effective voltage

In this paper, a two-dimensional consolidation theory for soft foundation under vacuum preloading combined with electro-osmosis was established, which considers the exponential reduction of the effective voltage with time. Then, an analytical solution for excess pore water pressure was derived, and the calculation formula for average degree of consolidation was given. The accuracy of the proposed analytical solution was evaluated by validating it against numerical solution. Assuming that the vacuum degree is linear decrease along the depth, the influences of the reduction of the effective voltage and the decreasing of the vacuum degree to the consolidation behaviour were analyzed. The results show that the slower the reduction of the effective voltage is, or the larger the residual effective voltage is, the faster the dissipation of the excess pore water pressure and the larger the value of the negative excess pore water pressure in the foundation are, but the slower the consolidation is. Besides, the larger the reduction of the vacuum degree along the vertical drain depth is, the slower the dissipation of the excess pore water pressure and the smaller the value of the maximal negative excess pore water pressure in the foundation are. However, the influence of the reduction of the vacuum degree on the consolidation degrees is little. © 2019, Science Press. All right reserved.