Evaluation of the Horizontal Coefficient of Consolidation Determined by One Dimensional Consolidation Tests for Soft Saturated Soil

Abstract

When determining time of consolidation at a project site where a soft clay soil profile is present the coefficients of vertical and horizontal consolidation are key parameters, when vertical drains are used. The coefficient of vertical consolidation, cv , can be obtained with a consolidation test. The horizontal coefficient of consolidation, ch, is typically estimated or determined by field tests. For this project the ch value was obtained by consolidation laboratory test. Ten consolidation tests were performed on five samples obtained at different sites in Puerto Rico. Five consolidation tests were performed to provide vertical drainage and the other five were performed so radial drainage would be provided. The experimental results were compared to empirical values provided by the Federal Highway Authority of Transportation. Values of ch, can be assumed to be equal to 1 to 2 times the cv value and would be a conservative value to determine the time of consolidation for a given project. Further field studies such as trial embankments may be performed to better understand the effect of the soil profile to the values of ch. Key Terms- Drains, Horizontal Coefficient of Consolidation, Saturated Clays, Vertical Coefficient of Consolidation.