Finite Element Analysis of Lattice-Shaped Ground Improvement by Cement-Mixing for Liquefaction Mitigation

The dynamic behavior of lattice-shaped ground improvements by mixing with cement was investigated using numerical analysis. Three-dimensional effective stress finite-element analyses were conducted to examine the effects of dimension and strength of the improved ground on the potential for liquefaction mitigation. In these analyses, both elastic and elasto-plastic models were used for expressing the behavior of the improved ground, where the elasto-plastic model can describe the post-peak stress-strain behavior of cement-treated soils. The numerical results suggested that the improvement area ratio and the elastic modulus of the cement-treated soil affect the potential of the improved ground for liquefaction mitigation. Moreover, numerical analysis using the elasto-plastic model showed that partial failure of the improved ground causes no considerable reduction in the potential for liquefaction mitigation. Since such partial failure of improved ground can be taken into account appropriately, the analysis using the elasto-plastic model provides an adequate solution for the performance-based design of a lattice-shaped ground improvement.