• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.767-772
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• 2003

The clay which transported into a pond under the high water content condition have no effective stress which develop from the starting point of sedimentation and self-weight consolidation. Since sedimentation and self-weight consolidation dependent on self-weight of solids is made progress over a long time, to accelerating it have many advantages in the economic view In this paper, sand spreading method which is one of sedimentation and self-weight consolidation acceleration method is studied through a series of experiments considering the mixing ratio of sand and clay. The test results show that the mixing ratio of clay and sand of 1:0.2 is the biggest rate of consolidation and the pouring at the end point of sedimentation considerably effects on consolidation rate.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.264-271
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• 2005

Sand pile method, such as sand drain method and sand compaction pile method, has been popularly used as an improvement method for soft clay grounds. The effect of accelerating consolidation of soft clay grounds has been evaluated with Barron's solution. By the way, the consolidation behavior of soft clay ground with sand piles strongly depends on both the nonlinear mechanical interaction between sand piles and surrounding clays and the degradation permeability of clays. In this paper, the method for determining consolidation parameters of soft clay ground with sand drains by using Barron's solution was proposed, through a series of numerical simulations. Through the method, the change in both volume compressibility and permeability during consolidation was reasonably evaluated.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.520-527
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• 2000

In the present study, the analytical approaches of vacuum consolidation with horizontal drains were proposed, For dissipating rapidly pore-water in hydraulic fills, vacuum consolidation method applied vacuum pressure in horizontal drains is developed. In the analytical approaches, the governing equation is based on two-dimensional finite strain consolidation theory and the boundary conditions of horizontal drains are considered in applying negative pore-water pressure occurred by vacuum pressure, Also, parametric studies to vacuum pressure and installation pattern of horizontal drains are carried out.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.619-627
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• 2008

In this study, through dissipation test of DMT predicted Horizontal Coefficient of Consolidation at marine clay. CPTu Dissipation test, laboratory consolidation test compared with $C_v$, through it examined application. The result, DMT calculated horizontal coefficient of consolidation by $P_2$-Log(t) method of DMT-A method and C-$\surd$t(min) method. This horizontal coefficient of consolidation calculated larger than $P_2$-Log(t) method. $P_2$-Log(t) method of DMT, Torstensson of CPTu and Houlsby & Teh(1991) appeared similar to tend. This approximate value is possible application in marine clay. It'll need to study continuously through collection of data.

• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.31-38
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• 2009

A continuous, fast, and convenient experimental method, replacing recent tests such as standard oedometer or self weight consolidation test, is needed for the determination of the consolidation behavior of unformed soft soils. This study introduced the seepage induced fast consolidation test using the flow pump technique. It can obtain the consolidation characteristics of unformed soft soils conveniently and fast. The seepage induced consolidation test apparatus consists of a modified triaxial cell, differential pressure transducer, flow pump, and displacement transducer. The test continuously proceeds with starting seepage forces induced consolidation, loading consolidation, and permeability test on the same sample. In addition, this test result was compared with the standard oedometer test result to make this method valid. From this study it was found that this method is a convenient and time saving effective method for obtaining data required for calculation of consolidation settlement of unformed soft soils.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5C
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• pp.201-208
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• 2010

In this study, the ground settlement was investigated by using monitoring data of the test sites where vacuum consolidation method and surcharge method were applied for improving deep soft soil. The monitoring data are chosen in ${\bigcirc}{\bigcirc}$ area port construction site reclaimed with very soft dredged clay. These data are analyzed to compare the consolidation characteristics between the different loading methods for soil improvement. Through analysis of the loading time, it is shown that the ground settlement reaches its allowable value under vacuum consolidation loading by about 45% faster than that of the surcharge loading consolidation. This could be explained that vacuum consolidation method makes the isotropic consolidation condition so that the time for reaching a certain final preloading without soil failure can be shortened.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.216-223
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• 2005

The coefficient of consolidation has been evaluated using the conventional oedometer tests based on the one-dimensional consolidation theory. In the field, however, the actual response of the soil will be subject to the three-dimensional condition during consolidation. In this research, a new estimation method of the coefficient of consolidation for the various stress-deformation conditions was proposed. The good agreement between the computed dissipation of pore pressure and the measured data confirms the usefulness and the applicability of the proposed method to predict the exact rate of consolidation.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.444-450
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• 2000

This study was performed to analyze the degree of consolidation by the dissipation of excessive pore water pressure and final settlement prediction methods of the very soft clay. Hyperbolic method, Asaoka method and curve fitting method were used to compute the degree of consolidation. The degree of consolidation with excessive pore water pressure were used to compute, which considered the dissipation time with embankment construction. The degree of consolidation that was obtained by the peak excessive pore water pressure was less than in the case of the dissipation excessive pore water pressure. And, the degree of consolidation by the total settlement was nearly the same value that of layer settlement. The degree of consolidation that was obtained by excessive pore water pressure was larger than in the case of the settlement.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.504-510
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• 2009

Dredging and Reclamation which have been conducted steadily for creation of new coastal area have demerit that takes a long time. Hence, a lot of researches on acceleration of self-weight consolidation is proceeding continuously. In this paper, 30 cases of laboratory self-weight consolidation tests were conducted to understand application of PDF method, one of the self-weight consolidation acceleration methods, to domestic dredged soils. Acceleration effect of self-weight consolidation was confirmed through comparison and analysis on completion time and settlement of self-weight consolidation for none installed case and 4 kinds of common used PBD installed cases.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.6
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• pp.35-41
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• 1996

The theory of consolidation has been achieved remarkable development in terms of theory such as finite consolidation theory, two dimensional Rendulic consolidation theory. Though those theories are well defined, the analysis is by no means straightforward, because associated properties are very difficult to determine in the laboratory, Therefore Terzaghi's one dimensional consolidation theory and Barron's cylindrical consolidation theory are still widely used in engineering practice. The theoretical shortcomings of those consolidation theories and uncertainties of associated properties make inevitably some discrepancy between theoretical and field settlements. Field settlement measurement by settlement plate is, therefore, widely used to overcome the discrepancy. Ultimate settlement is one of the most important factor of embankment construction on soft soils. Nowadays the ultimate settlement prediction methods using field settlement data are widely accepted as a helpful tool for field settlement analysis of embankment construction on soft soils. Among the various methods of ultimate settlement prediction, hyperbolic method and Asaoka's method are most commonly used because of their simplicity and ability to give a reasonable estimate of consolidation settlement. In this paper, the reliability of hyperbolic method and Asaoka's method has been examined using analytical methods. It is shown that both hyperbolic method and Asaoka's method are significantly affected by the direction of drainage.