Variability of strength and deformation properties in lime–cement columns evaluated from CPT and KPS measurements

Abstract

The variability in the strength and deformation properties of soil improved by deep mixing with lime–cement columns is generally high. This variability can be taken into consideration by using a reliability-based design. In this paper, the strength and deformation properties of soil improved by lime–cement columns have been evaluated using two different penetration test methods: the cone penetration test and the column penetration test. The properties were characterised by the mean, variance and scale of fluctuation, and each test method is analysed and discussed with a focus on its influence on the evaluation of the design value. The study shows small differences in variability of test data obtained by the two test methods. The choice of test method thus has only a small impact on the evaluation of the design value. Moreover the study shows the need for further work on the correlation between the penetration resistance and the strength and deformation properties of lime–cement columns.