• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6C
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• pp.321-329
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• 2008

In this study, a series of column test as a way in order to make up for the weakness point of the conventional acceleration method were conducted to both propose the suction board drain method and grapes the specific improvement character of this method as a result of a sort of plastic drain board and a phase of vacuum pressure conditions. On this occasion, the study focused on computing the effective factors of the fittest Suction board drain method affected by each condition through confirming the settlement generated during the test, the water content reduction and stress increase effect occurred arising from the test, and the ratio of consolidation related to the improvement period. In accordance with the shape of core and that whether the core is attached to the filter(pocket or adhesion), the castle type of adhesion and the column type of pocket are more efficient than the others as a consequence of the test to find out the improvement effect depending on each drainage such as a castle type, coil type, harmonica type, column type of pocket and a castle of the adhesion. In case of the step suction pressure, the shorter the period of $-0.8\;kg/cm^2$ as a final step of the suction pressure is, the better the improvement is. In addition, the correlation between degree of consolidation per each suction pressure level and duration of application was drawn as a curve and the point of inflection on this curve was provided to determine the duration period to maximize the consolidation.

• Journal of the Korean Geotechnical Society
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• v.30 no.10
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• pp.33-44
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• 2014

The preliminary design of suction pile as the supporting system for concrete floating structures was performed for the pilot project of the southwest coast area in Korea. Prior to starting design work, site conditions of the area including ground and hydraulic conditions, and a 100-year return period external force were throughly evaluated. The suction pile for mooring of the offshore floating structures has to satisfy the lateral resistance against external force as well as the penetration ability according to the soil conditions such as soil types, shear strengths, effective stresses, and seepage forces. In the design, the required penetration depths, which were stable for lateral resistance, were evaluated with the diameters of cylindrical suction pile as the final installing ones. And the design suction pressures at each penetrating depths, at which sand boiling did not occur, were assessed through the comparison of penetration and penetrationresistance forces. As a result, it was impossible for suction piles with the diameter range of 3.0~5.0 m to penetrate into required penetration depths. On the other hand, suction piles with the diameter range of 6.0 m and 7.0 m satisfied both the horizontal stability and the penetration ability by design suction pressures at the required penetration depths of 8.5 m and 8.0 m, respectively.