Updating Predictive Models for Vertical Swell Percentage of Expansive Clays

Abstract

Since the publication of the Israeli swelling model in 2011, new swelling test results have become available (all together on 897 undisturbed clay specimens), enabling an updating of the existing swelling model. Thus, it is logical to update this existing model to obtain a more accurate prediction of vertical swelling under a given vertical pressure exerted on the clay under consideration. This paper concentrates on the required updating, together with (a) a search for modified independent variables for the model equations and (b) a division of the 897 undisturbed specimens into two separate groups, one for the A-4 and A-6 material and the second for the A-7-5 and A-7-6 material, in order to enhance the accuracy of vertical swelling prediction. The final recommendation is to use two swelling models (the general one for the A-7-5 and A-7-6 material and the specific one for the A-4 and A-6 material), based on modified independent variables listed in the paper.