• Geotechnical Engineering
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• v.18 no.7
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• pp.21-26
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• 2002

• Geotechnical Engineering
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• v.25 no.9
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• pp.30-41
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• 2009

• Journal of the Korean GEO-environmental Society
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• v.5 no.3
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• pp.31-39
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• 2004

The bored pile is widely used as a low noise and vibration piling method in Korea. However, there is design tendency to minimize the friction capacity of the bored pile because of uncertainty and the quality control specification is not set up. This research analysed the strength characteristics of cement paste after the uniaxial compression test with various condition. Test results show that the compressive strength of cement paste with w/c=0.83 was up to $156.0kgf/cm^2$, and the lower w/c ratio and the longer age, the strength of cement paste increased. Also the higher soil mixing ratio, the strength of soil cement decreased, and too high soil mixing ratio caused the malfuction of soil cement. Also this research analysed the 188 dynamic pile test results which were performed before and after hardening of cement paste. Analysis result showed that the average ultimate unit friction capacity was $9.1tf/m^2$ and this result surpassed the common design criteria of the bored pile.

• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.39-47
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• 2004

The SCP(sand compaction pile) method which is a vertical reinforcing technique for soft ground using a sand compaction pile has received increasing popularity in Korea. Currently, there are different methods to evaluate the bearing capacity of the reinforced ground by the SCP method. However, a method that can consider the effect of the replacement ratio on the bearing capacity is not yet available. This study investigated the effect of the replacement ratio on the bearing capacity of the reinforced ground by the SCP method. The study involved laboratory experiments which were conducted on a centrifuge facility. Test conditions included various ranges of replacement ratios (20, 30, and 40%), centrifuged consolidation, and loading. From the results of the study, a method which can evaluate the bearing capacity of the reinforced ground was proposed and verified using the weighted average of the replacement ratio.

• Journal of the Korean Geotechnical Society
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• v.23 no.6
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• pp.37-51
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• 2007

In this study, pile load tests have been carried out to develop new P-y curves and then, to investigate the effects of pile rigidities on laterally loaded offshore drilled shafts in Incheon marine clay. This paper consists mainly of two parts: the first part, performance of a series of lateral load tests on small- and full-scale piles under one- and two-way loadings and the second part, comparison between the measured and predicted results by using O'Neill's and Matlock's clay models. Based on the results obtained, it is shown that relatively good agreements in bending moments and lateral displacements were obtained between the measured results using calculated P-y curves and predicted ones by O'Neill's and Matlock's clay models. The cases were considered with varying rigidity factors based on pile diameter, length and subgrade soil reaction. Through comparisons, it is found that soil P-y curve influences highly the behavior of flexible pile rather than that of rigid pile.

• Proceedings of the Korean Geotechical Society Conference
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• 1997.10a
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• pp.409-416
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• 1997

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.533-540
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• 2008

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2C
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• pp.41-49
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• 2009

Due to the increased size of civil infrastructure and the cost of materials, the needs exists for utilizing large sized cast-inplace piles in lieu of conventional precast piles. Among them, the barrette pile has become more commonly used in fields where a diaphragm wall is the retaining wall, to improve workability and economical efficiency, and to ensure hole stability under deep soil layers. In this paper, the bearing capacity and displacement characteristics of the barrette pile are evaluated by using the bi-directional loading test data obtained from four different sites. In addition, the design value of pile shaft resistance, ${\beta}$, is assessed with previous literatures and load transfer analysis. Finally, numerical analyses were performed to analyze the load-displacement behavior, and the interface effect on the piles, using the 3-dimensional finite element method.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.129-137
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• 2015

Recently, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. Jeju island has optimum condition for constructing a wind energy farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can not support sufficiently the structure. One of the most obvious applications of the pressuremeter test is the solution of the problem of laterally loaded piles. A hyperbolic non-linear p-y criterion for rock is developed in this study that can be used in LPILE program, to predict the deflection, moment, and shear reponses of a shaft under the applied lateral loads. Finally, a comparison between the predicted and measured response at two different sites is shown to give an idea of the accuracy of the IFP method.

• Geotechnical Engineering
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• v.12 no.2
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• pp.19-32
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• 1996

Based on Trifuilac's empirical model to transform earthquake acceleration time history in the time domain into Fourier amplitude spectrum in the frequency domail an earthquake scaling technique for simulating the earthquake record of certain magnitude as the required magnitude earthquake was suggested. Also, using the earthquake record of magni dude(M) 5.8, the simulated earthquake of magnitude(M) 8.0 was established and its application to dynamic testing system was proposed. The earthquake scaling technique could be considered by several terms : earthquake magnitude(M), earthquake intensity(MMI), epicentral distance, recording site conditions, component direction and confidence level required by the analysis. Albo, it had an application to the various earthquake records. The simulated earthquake in this study was established by two orthogonal horizontal components of earthquake acceleration-time history. The simulated earthquake shaking could be applied to the dynamic pile load test for the model tension pile and the model compressive open -ended piles driven into the pressure chamber. In the static pile load test, behavior of two piles was very different and after model tension pile experienced 2 or 3 successive slips of the pile relative to the soil, it was failed completely. During the simulated earthquake shaking, dynamic behavior and pile capacity degradation of two piles were very different.