ANALYTICAL SOLUTION AND ANALYSIS FOR CONSOLIDATION OF SAND-DRAINED GROUND CONSIDERING THE TIME-DEPENDENT WELL RESISTANCE AND RADIAL-VERTICAL FLOW

Based on the assumption proposed by Deng et al that the permeability coefficient of drains decreases with time in the form of an exponential function, and on that the radial-vertical flow of soil is considered, the governing equation for consolidation of sand-drained ground is derived and the analytical solution is obtained by using separated variable method. The correctness of the solution is verified by comparing the degenerate solution of the study with the existing analytical solution and the analytical solution with the finite difference solution. According to the solution, the influence of consolidation behavior of sand-drained ground is analyzed. The analysis shows that the consolidation rate of sand-drained ground decreases with the increase of well resistance factor \alpha whether the vertical flow is considered or not, and that the variation of well resistance has an important influence on the consolidation behavior of sand-drained ground in the later stage of consolidation. When the radial-vertical flow is considered, the final average consolidation degree can reach 100% with different \alpha. The consolidation rate of sand-drained ground is accelerated by the vertical flow, and the consolidation rate increases with the increase of the vertical permeability coefficient k_v. When the ground thickness H is thin, the vertical permeability coefficient k_v has a great influence on the consolidation behavior of sand-drained ground in the initial stage. When the ground thickness H is thick, the vertical permeability coefficient k_v has a great influence on the consolidation behavior of sand-drained ground in the later stage.