• Journal of the Korean Geotechnical Society
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• v.20 no.3
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• pp.107-117
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• 2004

This paper is to investigate the reinforcing effects of newly devised Tire-cell mat made of waste tires in sand. Parametric study on number of connection bolts between Tirecells, relative density of sand, embedded depth, number of reinforced layers and width of Tirecell mat was made by using plate loading tests. It is found that the number of connection bolt was enough to maintain the given pressure. The bearing capacity ratio(BCR), which is defined as the rate of ultimate bearing capacity of reinforced soil to that of unreinforced soil, is the highest at the lowest density. And the reinforcing effect can be obtained in case of embedded depth within 1.0B, where B is loading width. Also settlement reduction is the highest at the lowest density of sand. The effect of number of Tirecell reinforced layers with 0.4B to 0.5B interval is limited to 2 layers and further reinforcing effects can not be obtained beyond 3 layers. Especially, the bearing capacity increased remarkably at 1 layer of reinforcement and the degree of increase was small from 1 layer to 2 layers of reinforcement. The effect of mat width of Tirecell was not significant because of high stiffness of Tirecell although the maximum bearing capacity was shown at the 2.0B mat width and the reinforcing effects of Tirecell, in general, was prominent compared with those of commercial Geoweb.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.285-292
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• 1999

The cyclic plate load test were peformed to determine the behavior of reinforced soft ground with multiple layers of geogrid. Five series of test were conducted with varying the soil profile conditions which including the ground level, type of soil, and the thickness of each soil layer. The plate load test equipment was slightly modified to apply the cyclic load. Based on the cyclic plate load test results, the bearing capacity ratio(BCR), subbase modules, shear modules, the elastic rebound ratio, and reinforcing parameters are presented.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.47-58
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• 1989

This paper treats the vibration analysis of a simply supported rectangular plate stiffened with viscoelastic beams. The effect of viscoelastic beams on the vibration of the plate is analyzed by using Dirac delta function and the equation of motion can be expressed only one equation. The frequency equation is obtained by applying Laplace transformation. The effect of volumes, numben and aspect ratios of beam on the frequency of the plate is analyzed.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.3
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• pp.21-28
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• 1989

The optimun laminated composition of the stiffened composite plates is studied from the view point of buckling strength. The finite element method is applied to the buckling analysis of the composite plates taking into account the effect of shear deformation through the plate thickness. The stiffened plate model is discretized using plate thickness and symmetrically stacked. Parametric study is carried out for the selection of the optimum laminate structure; optimum fiber angle sequence through the thickness. Laminate structure of $[-45^{\circ}/45^{\circ}/90^{\circ}/0^{\circ}]$, is found to give the best buckling strength. For the case of that layer number is more than eight, best result is obtained when layers of the same fiber angle are put together, leaving the laminate has the same fiber angle sequence as a whole.

• The Journal of Engineering Geology
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• v.2 no.1
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• pp.19-35
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• 1992

aThe elastic properties of the fault zone (width; 3~12m), the shattered zone (width; over 40m) and the fresh rock zone distributed under the core foundation of fill dam in granitic gneiss have widely different range. The deformation moduli of the fresh rock zone, the fault zone and the shattered zone obtained from in situ rock tests - Plate Load Test and Bore Hole Deformation Test - show a range of $42,000~168,000kg/\textrm{cm}^2,{\;}963~2,204kg/\textrm{cm}^2{\;}and{\;}1,238~2,098kg/\textrm{cm}^2$, respectively. The differential settlements hetween the fault zone and the fresh rock zone are expected after the dam construction. Therefore, the displacement of foundation and concrete fill are evaluated using FEADAM 84 program of finite element analysis. The geometric distribution of discontinuifies obtained from the site mapping and drilling is considered in the finite element analysis. The analysis shows that the differential settlements between the fault zone and the fresh rock zone is about 6cm, while that of concrete fill is within 0.5cm.

• Journal of the Korea Concrete Institute
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• v.20 no.3
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• pp.271-282
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• 2008

Specific joint devices composed of end-plates and through bolts are under development to assemble steel beams to PC columns efficiently by dry construction method for the PCS structural system, of which major structural components are precast concrete columns and steel beams. Seismic performance of the joint devices had been evaluated by experimental tests in the previous studies and it was showed that all the performance requirements regarding to strength deterioration, stiffness degradation and energy dissipation capacity were satisfied to the criteria of ACI requirements, but the initial stiffness was not. In order to find out possible causes of the insufficient rigidity of the joint devices and provide the proper measures to improve the performance of the joint accordingly, numerical analyses were carried out by using ABAQUS. Parameters, such as thickness of neoprene pad, conditions of surface between PC column and end-plate, magnitude of pretension forces of through bolts, stiffness of end-plate were taken into consideration. As the result, it was found that the rigidity of the PCS system was negatively affected by the magnitude of initial gaps between PC columns and end-plates, and insufficient stiffness of neoprene fillers and end plates. In order to improve the initial stiffness performance of the joints, measures such as increase of the magnitude of pretension forces on through bolts and increase of the stiffness of end-plate by reducing the bolt pitch and providing adequate stiffeners are recommended.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.714-721
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• 2018

In this study, we investigate a design technology intended to radically increase the buckling strength of vertically curved panels. Recent studies proposed a buckling strength formula which properly reflects the effect on the local plate buckling strength of flat plates when they are stiffened by closed section ribs. Herein, we attempted to quantitatively evaluate this effect on curved panels and to reveal the correlations with the design parameters. The commercial finite element software, ABAQUS, was used to build a three dimensional numerical model and numerical parametric studies were conducted to evaluate the variation of the buckling strength. In the case of flat panels, the local buckling strength of stiffened curved panels increases proportionally with increasing rotational stiffness of the closed-section ribs. After attaining a limiting value, an obvious tendency was found that the local buckling strength of the stiffened curved panel would converge towards a fixed value when the panels are supported along both sides. The parametric studies performed using the influential design parameters confirmed that the estimated partially-restrained curved panel strength is well correlated with the proposed formula.

• Progress in Medical Physics
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• v.16 no.2
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• pp.77-81
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• 2005

To determine the appropriate method out of various available methods to measure build-up doses, the measurements and comparisons of depth doses of build-up region including the surface dose were executed using the Attix parallel-plate ionization chamber, the Markus chamber, a cylindrical ionization chamber, and a diode detector. Based on the measurements using the Attix chamber, discrepancies of the Markus chamber were within $2\%$ for the open field and increased up to $3.9\%$ in the case of photon beam containing the contaminant electrons. The measurements of an cylindrical ionization chamber and a diode detector accord with those of the Attix chamber within $1.5\%\;and\;1.0\%$ and after those detectors were completely immersed in the water phantom. The results suggest that the parallel-plate chamber is the best choice to measure depth doses in the build-up region containing the surface, however, using cylindrical ionization chamber or diode detector would be a reasonable choice if no special care is necessary for the exact surface dose.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.457-462
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• 2022

This study is about the case applied of a shallow foundation reinforcement method for a low/mid-rise building where a relatively small load is applied by using a soil stabilized material that utilizes recycled resources. First, laboratory mixing test was conducted for four mixing ratios in order to derive the optimal mixing ratio in the field. Using the derived optimal mixing ratio, it was applied as a shallow foundation for the building in the field. The field application method used a simple process of compaction by the soil mixedure with the original soil and the soil stabilized material in the field. After field application, a plate bearing test was performed on one original ground and two improved ground to confirm the allowable bearing capacity. As a result of checking the bearing capacity, it was found that sufficient bearing capacity was exhibited.Therefore, it was confirmed that it can be used as a shallow foundation for the building.

• Journal of the Korean Geosynthetics Society
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• v.8 no.1
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• pp.33-40
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• 2009

The laboratory tests and field plate load test were carried out to evaluate the reinforcement effect of geocell for road construction. The geocell-reinforced subgrade shows the increment of cohesion and friction angle with comparison of non-reinforced subgrade. In addition, the field plate load test was performed on the geocell-reinforced subgrade to estimate the bearing capacity of soil. The direct shear test was conducted with utilizing a large-scale shear box to evaluate the internal soil friction angle with geocell reinforcement. The number of cells in the geocell system is varied to investigate the effect of soil reinforcement. The theoretical bearing capacity of subgrade soil with and without geocell reinforcement was estimated by using the soil internal friction angle. The field plate load tests were also conducted to estimate the bearing capacity with geocell reinforcement. It is found out that the bearing capacity of geocell-reinforced subgrade gives 2 times higher value than that of unreinforced subgrade soil. The settlement and the distribution of deformation were also estimated by using the finite element method. The magnitude of settlements on the geocell-reinforced subgrade and unreinforced subgrade are 6.8cm and 1.2cm, respectively.