Abstract
Consolidation settlement of two Holocene marine clays improved by prefabricated vertical drain is analyzed in order to investigate the applicability of Constant Rate of Strain consolidation test by using the stress-strain relations determined by the test carried out at a strain rate of 0.02%/min. The clay deposits, found at Yokohama, Japan and Banjarmasin, Indonesia, are slightly to moderately overconsolidated. Since the final stresses inside the ground due to construction works are close to consolidation yielding stresses, settlement behavior of the clays is analyzed by considering their state of overconsolidation. Moreover, because the compressibility of clays significantly changes during the conversion from overconsolidated state to normally consolidated state, the analysis considers non-linearity in stress-strain relations. It is confirmed, from the comparison between the actual settlement and the result of the analysis, that Constant Rate of Strain consolidation test can be applied directly to detect the stress-strain relations mobilized in the field when clay deposit improved by vertical drain is concerned.
