Performance-based evaluation method for treated ground

Owing to the non-uniformity of improvement and the spatial variability of soil properties, sandy ground treated by the solidification method to prevent liquefaction exhibits greater spatial variability in shear strength than naturally depositted ground. This study expressed the spatial variability of shear strength using random field theory and modeled the reduction of soil strength due to the ground liquefaction during an earthquake. In this study, we used the results of our investigations on sandy soils improved by penetration grouting method, but this method is also applicable to cemented soils. We conducted a bearing capacity analysis using Monte Carlo simulation based on the finite element method, FEM, and shear strength reduction method. Furthermore, the deformation behavior owing to the dissipation of excess pore water pressure after liquefaction was investigated stochastically and statistically. The findings were used to propose a novel performance-based evaluation method for bearing capacity and flatness that indicates performance index values to be met for runways after an earthquake.