Coefficient of consolidation from piezocone measurements

Pore pressure dissipation tests were carried out employing two miniature piezocones, with areas of 1 cm2 and 5 cm2, in a bed of reconstituted kaolin. By using independently determined values of the coefficient of consolidation, the results were interpreted to derive appropriate values of rigidity index for use with the theory of Teh & Houlsby. In accordance with the theory, different filter positions on a piezocone (tip, face and shoulder) were not found to require different values of rigidity index. However, the importance of allowing for initial load relaxation at the commencement of the dissipation test was demonstrated, and there appeared to be a systematic effect of piezocone size.