EFFECT OF SOIL CEMENT COLUMN SPACING AND AREA REPLACEMENT RATIO ON EMBANKMENT BEARING CAPACITY: A QUEENSLAND CASE STUDY

Abstract

This paper investigates the effect of soil/cement column diameter and spacing on bearing
capacity beneath a road embankment situated on normally consolidated estuarine deposits in the South East
Queensland region. The modelling was undertaken using the Finite Element method and the results are
discussed with respect to the variation in parameters as described. A site investigation was undertaken
during the planning stages for construction of the embankment to establish the soil profile on the site. A
range of laboratory tests were performed on the undisturbed sample obtained during the investigation. The
results of the laboratory tests and several alternative established methods were utilised to establish the Plaxis
input parameters as discussed in this paper. The results of the analysis reveal a direct relationship between the
ultimate bearing capacity and the area replacement ratio, providing a practical tool for estimating soil cement
column spacings to achieve a required bearing capacity in South East Queensland conditions.