• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.194-201
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• 2000

In this study the modified seismic coefficient method for seismic analysis of buried box structures is developed for practical purpose. The loading coefficient in the modified seismic coefficient method is determined from the results of the response displacement analysis. In the developed method adequate velocity response spectrum in accordance with soil condition is also needed to seismic design of buried box structures, In order to investigate applicability of the modified seismic coefficient method various analyses are performed with different parameters such as depth of base rock height and width of box buried depth and value of standard penetration test. Results from the modified seismic coefficient method are compared with those of the response displacement method in terms of the maximum bending moment and the location of it. From the comparison it is shown that the feasibility of the modified seismic coefficient method for seismic analysis of buried box structures.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.471-478
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• 2000

Ground movements are inevitably caused by tunnel construction in soft ground. In the design and construction of tunnels in urban areas, the potential effects of buried pipelines by ground movements are one of the important design cosiderations. Generally, the most common modes of failure of buried pipelines due to ground movements are tensile fracture of main pipelines, rotation angle and pull-out displacement at joints. In the parametric study, a wide range of conditions were considered, including tunnel diameter(D), tunnel depth(Z$\sub$0/), volume loss(V$\sub$ι/) and inflection point(i). Based on this results, design charts, which are applicable to assess potential damage of buried pipelines associated ground movements due to tunnelling, are developed.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.396-405
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• 2006

The visual analysis of buried channel (Be) devices such as buried channel MOSFETs and CCDs (Charge Coupled Devices) is investigated to give better understanding and insight for their electrical behaviours using a 3-dimensional (3-D) numerical simulation. This paper clearly demonstrates the capability of the numerical simulation of 'EVEREST' for characterising the analysis of a depletion mode MOSFET and BC CCD, which is a simulation software package of the semiconductor device. The inverse threshold and punch-through voltages obtained from the simulations showed an excellent agreement with those from the measurement involving errors of within approximately 1.8% and 6%, respectively, leading to the channel implanted doping profile of only approximately $4{\sim}5%$ error. For simulation of a buried channel CCD an advanced adaptive discretising technique was used to provide more accurate analysis for the potential barrier height between two channels and depletion depth of a deep depletion CCD, thereby reducing the CPU running time and computer storage requirements. The simulated result for the depletion depth also showed good agreement with the measurement. Thus, the results obtained from this simulation can be employed as the input data of a circuit simulator.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.49-55
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• 1994

A study was conducted to determine the effect of depth of burial, soil temperature and/or moisture on tuber sprouting of E, kuroguwai. Tubers were evenly distributed in the upper 30cm of soil. Tuber weight increased as depth of tuber formed increased. No dormancy in newly formed tubers was found, whereas mature tubers were dormant. When new tubers were subjected both to continuous $5^{\circ}C$ and to gradual decreasing temperatures regimes ranged from 20 to $1^{\circ}C$ for 30 days, the tubers remained non-dormant. Viability of tubers was reduced when buried at 5cm depth in dry and moist soil conditions, but no reduction was obtained when buried at 25cm depth, regardless of soil moisture conditions employed. Percent sprouting of tubers buried at 25cm depth increased with increasing duration of burial in three soil moisture conditions studied, wherease in dry and moist conditions percent sprouting of tubers buried at 25cm depth increased by 60-day burial and thereafter decreased. In submerged condition, tuber sprouting was greater when buried at 5cm depth than when buried at 25cm depth, and increased as duration of burial increased at the both depths.

• Journal of the Korean Institute of Gas
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• v.14 no.6
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• pp.1-6
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• 2010

River crossing pipelines have been being operated with buried depth of 1.2~4m underneath river bottom to prevent buoyance and external impact. River crossing pipelines have to show resistance to soil load and hydrostatic pressure. In this study, structural integrity of the river crossing pipeline subjected to soil load and hydrostatic pressure was evaluated by using FE analyses. Hoop stress increased with increasing buried depth under identical water height in case of without concrete encasement, however, hoop stress decreased with increasing water height under identical buried depth.

• Journal of the Korean Institute of Gas
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• v.14 no.6
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• pp.51-56
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• 2010

Records of accidents for buried pipeline across the river were gathered and causes were analysed. The results are intended to be utilized as basic data for determining a reasonable criteria for the depth of buried city gas pipeline crossing the river. Accident of river-crossing buried pipeline was mainly caused by flood. Sometimes corrosion was detected at the failed location of the pipe. In order to determine reasonable and efficient depth of burial of the pipeline, hydraulic evaluation of the river and structural analysis of the pipeline are necessary. Published data for the buried natural gas pipeline incidents were also investigated and summarized. Main causes of buried natural gas pipeline incidents were external interference and corrosion. However, the two main causes of incidents showed significant difference in the proportion of the entire incident, depending on burial environment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.86-93
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• 2016

To find the buried pipes and cavities, GPR detection were proceed by the type and depth of underground pipes and cavities buried in the Chamber. In the case of asphalt pavement and non-pavement, the exploration of buried pipe were easy than the concrete and reinforced concrete pavement. In the case of air cavity, the buried depth of 1 m was evaluated as the detection was possible.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.2
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• pp.104-108
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• 2007

This paper deals with an approach to the reduction of potential rise according to the buried depth of structure. In order to analyze the surface potential rise of structure, an electrolytic tank which simulates the semi-infinite earth has been used. The potential rise has been measured and analyzed for types of structure using an electrolytic tank experimental apparatus in real time. The structure models were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. When a test current flowed through structure models, potential gradient was the highest value in case of the outline frame type(structure model A). The distributions of surface potential rise are dependent on the resistivity and absorption percentage in concrete attached to structure model.

• Geomechanics and Engineering
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• v.16 no.1
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• pp.97-104
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• 2018

The finite difference software Flac3D is used to study the influence of tunnel burial depth, tunnel diameter and lateral pressure coefficient of original rock stress on the stress and deformation of tunnel surrounding rock under sandstone condition. The results show that the maximum shear stress, the radius of the plastic zone and the maximum displacement in the surrounding rock increase with the increase of the diameter of the tunnel. When the lateral pressure coefficient is 1, it is most favorable for surrounding rock and lining structure, with the increase or decrease of lateral pressure coefficient, the maximum principal stress, surrounding displacement and plastic zone range of surrounding rock and lining show a sharp increase trend, the plastic zone on the lining increases with the increase of buried depth.

• Structural Engineering and Mechanics
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• v.20 no.1
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• pp.69-83
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• 2005

In many cases, underground structures are built using conventional above-grade structural systems to carry gravity load. This paper proposes the use of underground arches, termed "buried arches", to support gravity loads, wherein the horizontal thrust of the arch is equilibrated by soil pressure. Because the horizontal soil pressure increases with depth, the depth of the arch may be reduced as the depth below grade increases. Critical to the success of such an approach is a proper accounting of creep and shrinkage for arches made of reinforced concrete. This paper addresses the influence of equilibrium, creep, and shrinkage as they affect the design of the arch from a theoretical perspective. Several examples illustrate the use of buried arches for the design of underground parking structures.