• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.109-118
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• 2004

The consolidation of clay occurs with time lag, and this kind of lag can be separated into plastic lag and hydraulic lag. In this study, CRS tests were performed to research the effect of original secondary consolidation of the clay with respect to the characteristics of consolidation. Test results showed that plastic time lag was one of the key factors to get the preconsolidation pressure, and suggested the formula of the Quasi-preconsolidation pressure obtained from the relationship between consolidation time lag and consolidation pressures. In addition though the characteristics of coefficient of consolidation show a wide range of values, after passing the double preconsolidation point, it showed the tendency to converge into the constant value. The coefficient of permeability in normally consolidated state is related to its void ratio, and the permeability variables, n and $C_1$ were determined by the test results using the equation suggested by Samarasinghe. et. al. And then the equation was compared with the Kozeny-Carman's equation. Because of delayed compression caused by consolidation time lag, aging effect could be also found in the relationship between coefficient of permeability and void ratio.

• Journal of the Korean Geotechnical Society
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• v.24 no.7
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• pp.43-50
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• 2008

Structures are frequently built on a dredged clay layer overlaid by a soft marine clay deposit in coastal areas of Korea. Large consolidation settlement usually occurs in the case and this may cause damages of super-structures. So, the evaluation of long-term consolidation settlement is very important in design and construction. Therefore, in this study, a long-term consolidation characteristics of marine dredged clays are investigated. Firstly, the relationship of $C_{\alpha}/C_c$ on marine dredged clays near Gwang-yang Port was evaluated. Secondly, long-term consolidation characteristics of the pseudo-preconsolidated ground were evaluated.

• Journal of the Korean Geotechnical Society
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• v.30 no.2
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• pp.53-64
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• 2014

This study sets it's face to define effects of the various loading periods in normal consolidation area on clay's compression and long-term consolidation characteristics through a laboratory test using homogeneous remolded clay. Moreover, by carrying out a long-term consolidation test which diversifies initial consolidation applicable to effective overburden loading in the various loading period. This study intended to suggest the method predicting the final settlement on the basis of loading periods by comparing and analyzing compression curve's characteristics according to loading weight of each stage and increase in loading period when carrying out the standard consolidation test. From the test results, the study shows that as of the soft clay's compression characteristics on the basis of various loading periods, preconsolidation load has a tendency to be decreased slightly as the loading period is getting more and more longer at each step after initial consolidation load puts on the remolded clay which is caused by secondary consolidation's increase in the latter part of each phase. And those effects have an weaker influence on compression index in normal consolidation area at the same time as secondary consolidation brought out quasi-overconsolidation and stabilization of clay's structure, have an influence re-compression index is increased in overconsolidation area on the other hand.