• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1159-1164
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• 2005

Seismic analysis methods in use on ground structure are equivalentstatic analysis, response-displacement method and dynamic analysis etc. Equivalentstatic analysis does not considerdynamic effect, and dynamic analysis process is very complex. then 'Urbanrail transit earthquake-resistance design standard (2005.06)' is persuading that analyze by response displacement method that consider enough dynamic effect of ground structure statically. But, It is very complex and difficult to apply response-displacement method in the field. So, modified equivalentstatic analysis or pseudo static analysis that is easy to apply in the field and have rationality of design is practically used. In this study, I try to prescribe the applicable scale of structure and static analysis that have calculative effectiveness about response-displacement method by comparing and analyzing the result of each analysis method according to the scale of urban rail transit' box type concrete structure and by performing seismic analysis that apply modified equivalentstatic analysis, pseudo static analysis and response-displacement method changing the kind of ground, depth of bedrock, size of structure.

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.53-61
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• 2014

Sea gives us a lot of benefits and one of them is a role of transporting goods easily by ship. Accordingly the industrial area or the container yard is constructed either on the low sea or near the sea. Sea dredging ground is made by pumping them using dredge pump to the inside of embankment after dredging undersea soils. The dredging ground after pumping is in the slurry state but as time goes, consolidation by the own weight happens and evaporation happens at the surface of dredging ground. The evaporation causes the crest layer in the upper side of dredging ground. Under the crest layer there is still a soil of slurry state which has just little bearing resistance. This kind of characteristics makes it difficult to get a exact bearing capacity using the equations proposed until now. In this study we have performed simultaneously both the field loading tests and the cone penetration tests on the sea dredging ground. From the result of field tests, new experimental equation for the ultimate bearing capacity has been proposed. If we use the new equation, it is believed that some design of sea dredging ground could be more accurate.

• Journal of Conservation Science
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• v.20
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• pp.43-54
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• 2007

The Muryangsa temple five-storied stone pagoda (Treasure No. 185) was geographically located in the area of the Baekje Kingdom. The architectural style of the Muryangsa temple five-storied stone pagoda is the pagoda at the early Goryeo Dynasty that was succeeded technique of the Baekje Kingdom and form of the Shilla Kingdom. Because this pagoda is located outside during old time that it received serious petrological and biological weathering in rock blocks and occurred the center subsidence in the upper capstone. This study executed ground stability interpretation in order to know what central subsidence in the upper capstone occurred for soft ground. The ground stability interpretation used seismic survey, electrical resistivity survey and GPR survey by non-destructive method. As the result, the ground appeared in the condition which is good. Specially, high resistance zone appeared from electric resistivity survey which come to seem with ground reinforcement harden. Consequently, central subsidence condition in the upper capstone is not by the instability of ground, and is judged with the thing by the structure instability in rock blocks over the upper capstone. This will be applied basic data with the long-term monitoring or preservation countermeasure of the pagoda.

• Journal of the Korean GEO-environmental Society
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• v.19 no.3
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• pp.25-33
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• 2018

Piping is one of the most frequently occurring collapse type of a levee, and is often caused by roofing (backward erosion piping) at the ground-structure interface. Roofing is generally evaluated using creep ratio. However, creep ratio does not take into account the characteristics of the ground-structure interface. In this study, the roofing risk was investigated by using model test and numerical analysis considering the ground-structure interface characteristics. In the model test, it was confirmed that the piping potential decreased as the interface roughness increased, and this was applied to the numerical analysis. Existing numerical methods can not adequately simulate the particle behavior at the ground-structure interface because only the water level difference is considered. In this paper, particle behavior at the interface was investigated by performing seepage analysis and then, carrying out particle analysis technique simulating the boundary condition of the ground-structure interface. Analysis results have shown that the roofing resistance decreases as the ground-structure interface roughness decreases.

• Earthquakes and Structures
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• v.26 no.1
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• pp.17-30
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• 2024

Earthquakes can lead to substantial damage to buildings, with long-period ground motion being particularly destructive. The design of high-performance building structures has become a prominent focus of research. The double-story isolated structure is a novel type of isolated structure developed from base isolated structure. To delve deeper into the building performance of double-story isolated structures, the double-story isolated structure was constructed with the upper isolated layer located in different layers, alongside a base isolated structure for comparative analysis. Nonlinear elastoplastic analyses were conducted on these structures using different ground motion inputs, including ordinary ground motion, near-field impulsive ground motion, and far-field harmonic ground motion. The results demonstrate that the double-story isolated structure can extend the structural period further than the base isolated structure under three types of ground motions. The double-story isolated structure exhibits lower base shear, inter-story displacement, base isolated layer displacement, story shear, and maximum acceleration of the top layer, compared to the base isolated structure. In addition, the double-story isolated structure generates fewer plastic hinges in the frame, causes less damage to the core tube, and experiences smaller overturning moments, demonstrating excellent resistance to overturning and a shock-absorbing effect. As the upper isolated layer is positioned higher, the compressive stress on the isolated bearings of the upper isolated layer in the double-story isolated structure gradually decreases. Moreover, the compressive stress on the isolated bearings of the base isolated layer is lower compared to that of the base isolated structure. However, the shock-absorbing capacity of the double-story isolated structure is significantly increased when the upper isolated layer is located in the middle and lower section. Notably, in regions exposed to long-period ground motion, a double-story isolated structure can experience greater seismic response and reduced shock-absorbing capacity, which may be detrimental to the structure.

• Geotechnical Engineering
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• v.22 no.12
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• pp.10-16
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• 2006

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1996.06a
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• pp.21-21
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• 1996

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.628-635
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• 2008

A series of cone penetration tests in large calibration chamber were performed to investigate the effect of cementation level, relative density and vertical confining stress on cone resistance. From the experimental results, it was observed that the cone resistance is increased with increasing gypsum content, relative density, and confining stress. The increasing ratio on cone resistance of cemented sand compared with that of uncemented sand, that is IR($q_c$), was increased with increasing gypsum content and relative density, whereas it was decreased as the vertical confining stress increases. It was also observed that the cementation of granular soil influences the behavior of ground at low level of confining stress and its effect is diminished with depth.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.683-690
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• 2008

Steel-concrete composite columns are popular for superstructures of bridges, and the outside steel attached to the shaft increases the shaft resistance due to confining concrete. In this study, lateral resistance of steel-concrete composite drilled shafts was evaluated quantitatively based on numerical analysis when steel casings are used as structural elements like composite columns. Ultimate lateral resistance of composite drilled shafts with various diameters was numerically calculated through 3D finite element analysis. For that, elasto-plastic model with perfectly plasticity is involved to capture the ultimate load. A commercial FEM program, MIDAS-GTS, is used in this study. Real field conditions of the West Coast, Korea were considered to set up the ground conditions and pile lengths required for this parametric studies. Detailed characteristics of the stress and displacement distributions are evaluated for better understanding the mechanisms of the composite shaft behavior.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.23-30
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• 2019

In this study, we evaluated the applicability of proper embedded depth of fillings by examining the uplift resistance using spiral foundation and top base foundation. As a result of the model test, the maximum uplift resistance increased with the embedded depth. The maximum uplift resistance of each region was found to be 50cm depth. The spiral foundation was 335.14N of Sancheong, 312.32N of Seongju, 403.94N of Wanju, and the top base foundation was 745.06N of Sancheong, 1028.82N of Seongju and 950.76N of Wanju. The yield point after the elastic section in the stress-displacement graph of the top base foundation was calculated as the maximum uplift resistance. For this reason, farmers do not actually use top bases foundation. Therefore, it was considered that the additional load increase due to slip connector will not occur. Model test results show that the maximum uplift resistance increases with the purlinss installed under the ground. Therefore, additional comparative studies through purlins installation will be needed.