不均一性を考慮した固化改良地盤の性能評価に関する検討

抄録

Since the shear strength of cement-mixed soil is affected by cement content and mixing quality in addition to physical and mechanical properties of original soil, the in-situ strength of ground improved by cement mixing shows large spatial variation. Therefore, the amount of cement is conservatively set to satisfy the in-situ strength more than design strength considering the spatial variability in shear strength. The purpose of this study is to propose a rational method for setting the amount of cement by evaluating performance of improved ground taking the spatial variability of shear strength into consideration. In this paper, we report the results of a two-dimensional static residual deformation analysis to propose the relationship between deformation of embankment and the shear strength variability of the improved ground as an example of performance evaluation. The analysis was conducted for an embankment on a ground improved beneath the toes of slope. It was found that the settlement at the embankment top increased with the increase in the coefficient of variation for the similar average strength. The relationship between coefficient of variation and average strength for the similar settlement was further investigated, revealing that the amount of cement could be reduced by up to 11% when optimizing the number of agitations and the W/C ratio.