An Alternative Method for the Estimation of Coefficient of Vertical Consolidation of Coarse-Grained Lateritic Soils

Authors: Nwaiwu CMO, Anjorin JR, Mezie EO

DOI Info: N/A

ABSTRACT

Coefficient of consolidation (cv) is a very important parameter in the estimation and monitoring of settlement characteristics of soil for foundation design and other purposes. It is usually determined through an oedometer test using various methods. However, the irregularity of the dial reading versus root of time curve used to determine cv using Taylor’s method has been a challenge especially for soils with high sand content. Ten (10) lateritic soil samples were tested in the laboratory using an oedometer apparatus. The dial reading versus root of time graph was plotted for all the samples and cv determined in both normal fit (free hand method) and power function fit (power series method). The coefficient of determination (R²) was quite significant for the curves when fitted to power function with average values ranging from 0.871 to 0.986 across all samples. With the power curve closely approximating the theoretical U-T curve, it is expected that cv values from such would be more reliable. Descriptive statistics carried out for the cv values show high standard error, standard deviation and variance for cv values determined from free hand method when compared to power series method. Thus, fitting dial reading versus root of time curve to a power function could be a more reliable way of determining cv for coarse-grained soils using Taylor series method.

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