Effects of spatial correlation on the compression behavior of a cement-treated column

The strength of soil treated by cement deep mixing varies greatly, even at a single column, because of the variability of in situ soil properties, the variability of mixing effectiveness, and other factors. The variation in strength would affect the entire behavior of the cementtreated column. This paper presents a numerical experiment that investigates the effect of spatial correlation on the unconfined compressive strength of cement-treated columns. Finite element analyses incorporating random-field theory were performed to simulate the unconfined compression behavior of full-scale column samples in which the material properties vary with respect to spatial autocorrelation. The numerical results indicate that spatial autocorrelation affects the compression behavior of full-scale cement-treated columns. The overall strength of the sample in the absence of spatial autocorrelation is slightly lower than that of the uniform sample of mean strength. On the other hand, the overall strength of the sample in the presence of spatial autocorrelation is significantly lower than that of the uniform sample of mean strength. These results suggest that spatial autocorrelation should be considered when evaluating the overall strength of full-scale cement-treated columns within a relevant design procedure.