Estimating coefficient of consolidation from piezocone tests: Discussion

Abstract

The authors are to be commended for their assembling of such comprehensive data in a manner that can be used by practitioners. The discussers, having recently completed a similar research project for the South African Roads Board, are acutely aware of the large amount of effort required to obtain such information. The primary objective of our project was to verify and calibrate the use of the piezocone for the prediction of embankment settlements on recent alluvial deposits. The secondary objective was to estimate coefficients of consolidation from piezocone data and hence calibrate the prediction of times for settlements. The data base for this comprised: ( i ) se t t lement records fo r up to 15 years fo r 12 embankments; ( i i ) original site investigation laboratory test results, including cone penetration test (CPT) data; and (iii) piezocone results carried out recently for the project ( u 2 filter location, see Fig. I). At some of the embankments, since the subsoil conditions were variable, more than one case history could be reconstructed, with the result that a total of 25 separate cases were available. It is hoped that the results of the project will be published shortly. In the meantime, however, the essential findings are given below. Using the conventional equation to derive m, from cone data, viz., 0.i 1 10 100 im ioooo tm, m l n