• Journal of the Korean Geotechnical Society
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• v.33 no.11
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• pp.45-57
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• 2017

Temperature change affects consolidation behavior of soft clays. The increase of temperature in soft clays induces the increase of pore water pressure. The dissipation of the excess pore water pressure decreases volume and void ratio. Also, the consolidation rate is accelerated by high temperature which induces the decrease of viscosity of pore fluid. The effects of temperature on the consolidation behavior such as consolidation settlement, consolidation time, and pore water pressure were investigated in this study. A numerical analysis of hydro-mechanical (HM) and thermo-hydro-mechanical (THM) behavior was performed. The combination of heat injection and sand drain for consolidating the soft ground, with varying temperature (40 and $60^{\circ}C$) and sand drain diameter (40, 60, and 80 mm), was considered. The results show that the temperature inside soil specimen increases with the increase of the temperature of heating source and the diameter of sand drain. Moreover, the heat injection increases the excess pore water pressure and, accordingly, induces additional settlement in overconsolidated (OC) state and reduces the consolidation time in normally consolidated (NC) state.

• Journal of the Korean Geotechnical Society
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• v.23 no.4
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• pp.69-77
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• 2007

In this study, the consolidation behavior of clayey ground improved by vertical drain method was analyzed by the finite difference method based on the three-dimensional elasto-viscous consolidation theory, which can express the behavior of the secondary consolidation without considering the distinction of the normally consolidated and overconsolidated states. And the applicability of the elasto-viscous consolidation theory was discussed by comparing with the test results obtained from the model test of ground improved by vertical drain system. From these results, it is found that the amount of the settlement when the excess pore water pressure almost dissipated in the clay ground with vertical drains became smaller than that of the one-dimensional condition, and then the amount and rate of the residual settlement at secondary consolidation process became larger than those of the one-dimensional condition. finally, the effect of soil parameter on behavior of consolidation process was investigated by the results of a series of numerical analysis for the normalized and overconsoldiated states.

• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.73-81
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• 2002

Various CPT-based prediction models far profiling stress history of marine clay at the southern part of the Korean peninsula were investigated by using both statistical analysis and case history study. Preconsolidation pressures($\sigma'$p) and overconsolidation ratio(OCR) estimated by empirical correlations and cone penetration tests were compared with those of laboratory odometer test results. Stress history of marine clay determined by odometer test results was in general overconsolidated at below 10m depth from the mudline, whereas marine clay at below l0m depth from the mudline which has an around 0.3 overconsolidation ratio showed variable stresses and unstable states. Preconsolidation pressures were computed by both empirical methods of the Chen and Mayne(1996) and theoretical method of Konrad and Law(1987). It is estimated that Chen and Mayne(1996)'s prediction method based on pore water pressure is more reliable than any other prediction methods, and their method proved to be the most reliable for overconsolidation ratio estimation. However, it is recommended that Mayne & Holtz(1988) and Mayne & Bachus(1988) methods are more suitable than any other methods for predicting the overconsolidation ratio at an underconsolidated (OCR<1) clay. For these reasons, rather than making use of existing prediction models, development of site specific empirical correlations which considers local characteristics and site conditions may be required due to different local stress history and variable soil properties.