• Journal of the Korean Geotechnical Society
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• v.27 no.8
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• pp.17-30
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• 2011

A variety of in-situ geotechnical investigation methods are currently used to measure the properties of each site, but in-situ tests for "Intermediate Geomaterial (IGM)", which is the transitional geomaterial between soil and rock, have only limited application. In the United States, "The Texas Cone Penetrometer Test (TCPT)", which is the geotechnical investigation technology for IGM, is utilized to create foundation designs. This paper introduces "The Driving Cone Penetrometer Test (DCPT)", which can be performed using general geotechnical investigation equipment and also analyzes the correlation between various in-situ geotechnical investigation methods by applying DCPT on the ground. The results showed that the correlation between the driving cone penetrometer test (DCPT) and standard penetration test (SPT) was quite high. Additionally, the scope of DCPT properties was wide, depending on soil types.

• Journal of the Korean Geotechnical Society
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• v.26 no.5
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• pp.5-13
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• 2010

For the development of design chart for drilled shafts socketed into weathered zone, the 6 bi-directional pile load tests with load transfer measurements done in two in-situ sites were performed. Also, DCPTs were performed in each test point. Maximum unit skin frictions and maximum unit end bearing capacities from pile load test results were analyzed. Inter-relationships between DCPT's characteristics were also analyzed. In the soils, the inter-relationships of maximum unit skin friction and DCPT appeared so low. But in the weathered zones, inter-relationships between maximum unit skin friction / maximum unit end bearing capacity and DCPT were so high that the coefficient of correlation is over 0.70.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2C
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• pp.95-107
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• 2010

To calculate the end bearing capacity of a drilled Shaft socketed into the rockmass, the unconfined compression strength could be used. But it is difficult to find the unconfined compression strength because it is impossible to get undisturbed samples in weathered soils and rocks. So, to calculate the end bearing capacity, the existing bearing formula could not be used. In this study, for five zones (near pile tip, tip~lower 1D, tip~lower 2D, upper 1D~lower 1D, upper 1D~lower 2D), the relationships between the characteristic values of in-situ tests(SPT, DCPT PMT, BST) and the end bearing capacity of drilled shafts were analysed. As a result, DCPT results were represented the best credibility. Also, a design chart of end bearing capacity using DCPT was suggested.