• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1391-1398
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• 2009

The vibrating table method is widely used to estimate the minimum void ratio $e_{min}$. The existing method recommended in ASTM and KS F, however, can not consider the particle crushing during the vibrating table test. In this study, the particle cursing phenomenon was investigated by comparing vibrating table test with pluviation method using artificial sand (K-7). Vibrating table test for the artificial sand was confirmed which can crush of particle during the test. This study demonstrates that vibrating table test is an ineffective method to produce the more reliable $e_{min}$ of artificial sand.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1399-1406
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• 2009

Probability distribution of geotechnical properties is very useful information and it is used for evaluating the geotechnical properties itself and calculating probability of failure. In this study, probability distribution of compression index, recompression index, and void ratio are evaluated, and analysis results show that all property distributions satisfy normal and log-normal distribution.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1317-1323
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• 2009

A finite element analysis was performed for new earth retention system that is a kind of truss tower with non-supported excavation. A 2D finite element model was adopted in this study to investigate the behavior of the earth retention system. Just because this non-supported truss tower system is too complex to model in 2D plain-strain condition to itself, so have to simplify it by the conception of equivalent rigidity. The horizontal displacement of the wall and lateral earth pressure distribution on the wall were computed. And it is compared with NAVFAC design manual.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1181-1187
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• 2009

과잉간극수압의 소산 속도는 일반적으로 압밀방정식에서 정의하는 압밀계수에 의해 결정 되는데, 이 압밀계수는 투수계수와 체적압축계수의 관계로 얻어지는 흙이 특성이며 동일한 성질의 지반에서라도 측정위치에 따라 그 값의 편차가 심한 특성을 보인다. 이에 본 연구에서는 위치적 이질성이 있는 점성토 지반의 압밀과정이 균질한 지반에서의 압밀과 어떤 차이를 보이고, 위치적 이질성으로 인한 불확실성이 압밀소요시간이나 압밀속도에 미치는 영향에 대해 유한차분법을 이용한 수치적인 방법으로 고찰하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.923-932
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• 2009

Generally most of pile foundations are constructed with group pile rather than single pile. The study on efficiency and bearing capacity which are major elements for rational design of this group pile has been actively progressed, whereas there are truly only a few studies of negative skin friction working on group pile due to the consolidation of ground. The purpose of this study is to determine, among the elements of negative skin friction applied to pile, the occurrence modality of negative skin friction at center, side, and corner of $3{\times}3$ group pile using model test and, based on those observations, to propose the effective design direction of group pile.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1224-1231
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• 2009

1D Analysis have been using Design of SCP in order to improve the soft ground. But 2D Analysis is researching and developing to get more accurate results. Using 2D Analysis, suitable Numerical Analysis Model should be selected and be tested in many situations. In this study, Laboratory Model Tests are analyzed by Numerical Analysis Method. After selecting Numerical Analysis Model, it is being tested many conditions.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1188-1191
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• 2009

In this study, cyclic triaxial tests were performed with the samples which were anisotropically consolidated using irregular earthquake loading to consider in-situ condition and seismic wave. The consolidation pressure ratio(K) was changed from 0.5 to 1.0. The Ofunato and Hachinohe wave are applied as irregular earthquake loading and liquefaction resistance strength was estimated from excess pore water pressure(EPWP) ratio. As results of the cyclic triaxial tests, buildup of EPWP ratio increased as K value increased. It shows, that the isotropically consolidated sands is more susceptible to liquefaction than anisotropically consolidated sands under equal conditions such as confining pressure and dynamic loading.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.498-503
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• 2009

얕은기초의 침하량은 기초강성에 따라 크게 좌우되지만 기존의 이론적인 연구결과는 실무에 적 하기에 불충분하였다. 그러므로, 본 연구에서는 3차원 수치해석법을 이용하여 직사각형 기초의 길이비에 따른 강성 보정계수를 산정하고자 하였다. 우선, Mayne & Poulos(1999)가 정사각형 기초에 대하여 제안한 강성 보정계수와 비교하여 본 수치해석 기법의 적용성을 검증하였다. 그리고, 검증된 수치해석 기법을 적용하여 직사각형 기초의 길이비를 L/B=1, 2, 5로 달리하여 해석을 수행하였다. 그 결과, 동일한 기초강성에서 기초의 길이비(L/B)가 증가함에 따라 강성 보정계수 값이 점차 증가하는 결과를 보여주었다. 그러나 L/B=5 인 경우에는 강성계수가 10이상 되더라도 기초는 완전강성 거동을 보이지 않았다.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1126-1131
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• 2009

Suction Drain Method is soft ground improvement technique, in which a vacuum pressure can be directly applied to the Vertical Drain Board to promote consolidation and strengthening the soft ground. This method does not require a surcharge load, different to embankment or vertical drain method. In this study, Using Suction-CAIN program, which optimize th Suction Drain method, estimate validity Suction Drain method on deep soft ground

• 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.