• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.4
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• pp.96-104
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• 1991

The research effort has been focused on better calculation methods for the coefficient of consolidation under the theory of one dimensional consolidation. This research has been made available to engineers in the form of the computer program COMCv. The following conclusions can be drawn from the result of the engineering analysis, programming, and field observations. 1.Performing comparative study on six mehods(Taylor, Casagrande, Sivaram & Swamee,Su, Cour, and Scott) which can find out the coefficient of consolidation, the computer program COMCv is developed for each method. 2.Comparing the observed settlement and computed one in use of the coefficient of consolidation computed with COMCv, the result by the method of Sivaram & Swamee, Taylor, and Su is closer to the observed settlement.

• Proceedings of the Korean Geotechical Society Conference
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• 1992.10a
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• pp.121-130
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• 1992

Assessement of comsolidation characteristics of soft soil is very important in the project of soft soil improvement. In the design step, the consolidation characteristics of soil is determined by the laboratory tests (typically oedometer test), generally. But there is big differences between the condition of laboratory test and the condition of field(in situ). the differences results in the considerable difference between the predicted and measured consolidation behavior. This article analyzed the consolidation data of the "SOFT SOIL IMPROVEMENT PROJECT of the 2nd Namdong Industrial Complex at Inchon". The project was improving the road way net work in the 2nd Namdong Industrial Complex by preloading and sand pile method. Field instrumentation was performed at 10 points which consist of pneumatic piezometers, magnetic probe extensometers, inclinometers and electronic dipmeter. The results showed that there is big difference in the laboratory predicted consolidation behavior and field consolidadion behavior. Also there was big difference in the settlement behavior and pore pressure behavior. This article investigated the above factors by comparing the settlement, pore pressure and strength at different conditions.onditions.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.597-604
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• 2002

This paper reviews depositional environments of marine deposits along the Nakdong river and then analytical solution of self-weight consolidation considering artesian pressure is made to find consolidated state. It's known that this area is in the under-consolidated state by the artesian pressure(u$\_$a/=0.3kg/$\textrm{cm}^2$) and the distribution of the artesian pressure is not linear but parabola. In predicting consolidation settlement for soft grounds improved by vertical drain, it is emphasized that the self-consolidation by sudden dissipation of artesian pressure should be considered.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.513-523
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• 2022

The purpose of settlement management when treating soft ground through preloading is to determine the amount of settlement, check the progression of consolidation, and compare the settlement with the target settlement amount. Of the various methods available for predicting settlement based on measured data, the hyperbolic method was used in this study to analyze the settlement behavior of soft ground considering the creep behavior resulting from staged fill. Two versions of the method were used: the existing hyperbolic method, and a modified hyperbolic method. The existing hyperbolic method predicts the settlement amount using data for the final settlement section only during soft ground treatment through staged fill, for which the coefficient of consolidation behavior (k) was computed to give a predicted final consolidation settlement amount of S_r = 1.05 cm. In comparison, using the modified method, a predicted final consolidation settlement of S_r = 0.50 cm is obtained by considering the data for each staged fill section. These results show that the modified method considering data from the staged settlement was more accurate than the existing method considering data only from the final settlement section. This modification to the hyperbolic method therefore represents an improvement in performance over the existing method.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.706-712
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• 2022

Purpose: In this study, field experimental research was conducted to analyze the settlement characteristics of soft ground in the central inland region of Korea and use it in practice. Method: The design predicted values and comparative analysis were performed using the ten settlement measurement data actually measured in the field experiment. For the design prediction value, Terzaghi's one-dimensional consolidation settlement analysis was used. In the experiment, the surface subsidence plate was used for field measurement. Result: The settlement behavior of the predicted value and the actual value was generally similar, but in the settlement value, the actual settlement value showed a settlement behavior of 30% or less compared to the predicted settlement value. The rate of consolidation settlement in this study area was in the range of 9.6% to 27.0%, and the average value was 18.21%. It is analyzed that the prediction of the settlement amount of the silty soils distributed in the inland plains of the central region of Korea can be relatively overestimated. Conclusion: It is judged that precise ground investigation and detailed prediction are necessary because there is a possibility of over-design in the design for predicting the amount of settlement of the silty soils distributed in the inland plains of the central region of Korea.

• Journal of the Korean GEO-environmental Society
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• v.25 no.4
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• pp.5-12
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• 2024

In the case of creating a site in the reclaimed land (public waters), due to the nature of the coastal sedimentary ground, large-scale construction materials are required, It is necessary to utilize soft clay, which is inevitably generated during construction of the complex, as a fill material in terms of resource recycling and economic aspects (reducing the amount of embankment required). In this study, changes in the consolidation characteristics of cut-out disturbed soft clay due to the recycling of soft clay soil were identified, and a consolidation settlement design plan was proposed. Through the results of the consolidation test of the study site, the change in consolidation characteristics (compression index reduction, precede load uncountable) due to disturbance (cutting) was confirmed, the method of calculating (consolidation settlement) the filling clay layer as the composite target layer (consolidation target layer, loading load layer) was analyzed as a result consistent with the actual behavior.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.02a
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• pp.70-77
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• 1999

Consolidation settlements on soft clay are often large and potentially damaging to structures. Currently, large-scale projects are in progress in Korea. These structures will be constructed on both thick and soft clay layers, and so the accurate evaluation of magnitude of settlement is required at every step in design and construction. Especially, secondary compression play an important role in consolidation settlements on soft clay. Generally, the magnitudes of secondary compression are evaluated by laboratory and in-situ consolidation tests or by empirical $C_{a/}$ $C_{c}$ relationships. The empirical $C_{a/}$ $C_{c}$ may not be only economical, but a fast and powerful tool in estimating secondary consolidation settlement. However, databases of the $C_{a/}$ $C_{c}$ relationship for sites in Korea are currently insufficient. The purpose of this study is to investigate the relationship of $C_{a/}$ $C_{c}$, on marine clay near the southern sea in Korea. In this study a series of incremental loading consolidation tests (measuring base pore water pressure) are performed. It was found that the $C_{a/}$ $C_{c}$ on undisturbed marine clay equaled 0.0397. This value is similar to the value proposed by Mesri and Castro(1987) for inorganic clay and silt. and silt. and silt.

• Geomechanics and Engineering
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• v.2 no.2
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• pp.107-123
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• 2010

Ground settlements and pore pressure changes were monitored around a shallow tunnel constructed in clay till during the excavation and primary lining installation. The settlements above the tunnel continued to develop for up to 100 days after the primary lining installation. Triaxial compression tests were carried out to estimate the short-term and long-term deformation characteristics of the till. Numerical simulation was conducted to history match the field measurements, and thus, to quantify the settlements induced by ground stress relief, consolidation and creep. It was found that the surface settlements due to ground stress relief, consolidation and creep are 17, 12 and 71% of total settlement (about 44 mm), respectively. In addition, early installation of rigid concrete lining could be an effective means to reduce the settlement due to creep.

• Journal of the Korean Geotechnical Society
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• v.28 no.6
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• pp.31-38
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• 2012

In this present study, the long-term consolidation tests were performed using the remolded Kwang-Yang port clayey soil to clarify the effect of stress history and over-consolidation ratio (OCR) on the long-term consolidation characteristics of the soft clayey soil. For the over-consolidated state clayey soils, in case OCR exceeds 1.5, there are no great differences of secondary consolidation settlement and final settlement even if OCR increases from 2.0 to 3.0. Therefore, it has been understood that the value of OCR applied on the field site to reduce the secondary consolidation settlement and the final settlement is about 1.5. In addition, in order to investigate the relationship between the pre-loading period and the characteristics of long-term consolidation behavior obtained from the test results using the remolded Kwang-Yang port clayey soils, the influence on long-term consolidation behavior was not large though the pre-load was unloaded with the consolidation degree 70~80% exceeded.

• Journal of the Korean Geotechnical Society
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• v.22 no.12
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• pp.5-14
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• 2006

In general, the dredged ground was composed of a big difference of sediment shape through segregating sedimentary of finer soil in case of reclaiming by dredged coarse soils. Therefore, this study was performed to evaluate the change of settling velocity of flow, and the density of sedimentary which is based on settling tests and self-weight consolidation tests, and consolidation test by seepage force according to the percentage of coarse of Kunsan dredge soils. The Yano's method has been applied to estimate the settlement of self-weight consolidation in finer soils at design but it only considers pouring water content and elevation of interface, therefore the other method needs to be introduced for the exact prediction of the settlement of coarse soil in which the segregation sedimentation is occurring. In this study, the settlement of self-weight consolidation was calculated by the change of the density of segregating sedimentary of coarse and finer soils which was analyzed by Yano's method to extend a serious of researches. The self-weight consolidation by Yano's method will not reflect the segregated settling in dredging coarse soil under 40% of #200 passing percentage. As a result, the evaluation technique of settlement of self-weight consolidation considering a change of the density of segregating sedimentary is suggested as a reasonable method that considers the sediment shape of coarse soil.