2012 Volume 68 Issue 4 Pages 695-706
The strength of soil treated by cement deep mixing is highly variable, even at a single column, due to variability of in-situ soils, variability of mixing effectiveness, and other factors. Therefore the variability of strength has been considered in the design procedures of the improved ground. Normal or lognormal distributions have been adopted for the variability of the strength of the cement-treated soils so far. In several Japanese design procedures, the normal distribution is applied for the probability distribution of the cored-sample strength of the improved ground. However, there is little study in which the effect of the probability distribution of the cored-sample strength on full scale column strength is investigated.
This paper presents the numerical study which investigates the compression behavior of full scale cement-treated column with the strength field following normal and lognormal distributions. Firstly, the goodness of fit for normal and lognormal distributions against the cored-sample strength was evaluated using K-S test and AIC. Secondly, the finite element analysis was conducted to investigate the overall compression behaviors of the columns with the strength field following normal and lognormal distributions. The influence of the probability density function of the cored-sample strength on the overall compression strength was discussed. The numerical results indicated that the normal distribution fits the calculated overall strength of the column with the normal random strength field and the lognormal distribution fits that with the lognormal random strength field.
