• Journal of Korea Water Resources Association
• /
• v.45 no.2
• /
• pp.179-189
• /
• 2012

To simulate the transport of pollutant, a numeric model for the advection-diffusion equation with the decay term is developed. This is finite-difference model using the implicit method (with the weight factor ${\alpha}$) and Gauss-Seidel SOR(successive over-relaxation). This model is compared to the analytical solutions (of simpler dimensional or boundary conditions), and in the condition of Peclet number < 5~20, the result shows stable condition, and Crank-Nicolson method (${\alpha}$=0.5) shows the more accurate results than fully-implicit method (${\alpha}$=1). The mass of advection, diffusion and decay is calculated and the error of mass balance is less than 3%. This model can evaluate the 3-D concentrations of the advection-diffusion and decay problems, but this model uses only the finite-difference method with the fixd grid system, so it can be effectively used in the problems with small Peclet numbers like the pollutant transport in groundwater.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.8
• /
• pp.49-58
• /
• 2010

In this study, in order to investigate the characteristics of secondary consolidation in the soft clay ground, oedometer tests were carried out in a normally consolidated condition, and the consolidation characteristics of the soft clay ground were examined by the Finite Difference Method (FDM) based on the Elasto-Viscous model proposed by Yoshikuni. The consolidation tests adjusted the consolidation load increment ratio(${\Delta}p/p_0$) to 1.0 for the four cases with initial consolidation pressures of 0.8, 1.6, 3.2, and 6.4 kgf/$cm^2$. The long-term consolidation tests were examined by the tests that changed the load increment ratio to clarify the effect of consolidation load increment. Although the numerical analysis was delayed in the primary consolidation process, from the result of the numerical analysis of the laboratory tests, the applicability of the Elasto-Viscous model was verified from the agreement of the secondary consolidation process. Based on the developing of model ground consist of general soft clay, influences of consoliation parameters on the consolidation characteristics were studied by the numerical analysis.