• Journal of Korean Society of Transportation
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• v.30 no.4
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• pp.7-19
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• 2012

In this study of estimating the benefits of environmental materials, the CVM method used in environmental economics was applied to estimate the value of pedestrian environment improvement. After finding the Willingness To Pay (WTP) level of residents through CVM, this study attempts to calculate quantitative benefits from the pedestrian environment improvement. In this study, a survey targeting the inhabitants in Seongbuk-gu adjacent to a business area was carried out for pedestrian environment improvement considering form of payment, willingness to pay and such by establishing and showing several virtual scenarios depicting a quiet and comfortable pedestrian environment. As a result, the willingness to pay level of the Seongbuk-gu residents was 627 won of surcharge for pedestrian environment improvement per month. Additionally, the annual total benefits by pedestrian environment improvement was estimated within a range from 1,247,516,820 won to 286,305,110 won.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.3
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• pp.39-46
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• 1990

This paper was analized the thermal conductivity of polystylene (TENSAR- GEOGRID) embeding into the subbase through frost penetration depth, frost heave, change of bearing capacity, and soil moisture movement due to freezing, thawing and icing actions, and their results were as follows : 1.The change of temperature into the sub-base was much increased by the Tensar-Geogrid insertion, and the frost penetration and frost heave were decreased as the thinner of the insulation thickness but the thawing velocity of melting period was appeared to be faster in case of non-insulated. 2.The frost heave had a close relationship with the thickness of insulations which was reasonably included anti-frost effects. 3.The moisture content during the freezing period of upper layer of the insulation insertion was increased by 15 per cent but it was returned to initial state of the thawing period, and at the down layer temporarily increased by 10 per cent and returned to the original state at once. 4.The insulation was acted as a function of distribution of surcharge, and the settlement of the sub-base was about 1.5 mm under 15 tonnage of load and which was included within the allowable limits. 5.The sliding resistance due to the icing which was induced by the insulation insertion into the sub-base was appeared as more 40 per cent than noninsulation area, so that the insulations should be restricted on the place such as mountains, curved and cross area which were required the braking power under the traffics.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.91-99
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• 2008

Applicability of existing methods of predicting consolidation settlement was assessed by analyzing results of centrifuge tests modelling self-weight consolidation of soft marine clay. From extensive literature review about self-weight consolidation of soft marine clays located in southern coast in Korea, constitutive relationships of void ratio-effective stress-permeability and typical self-weight consolidation curves with time were obtained by centrifuge model experiments. For the condition of surcharge loading, exact solution of consolidation settlement curve was obtained by Terzaghi's consolidation theory and was compared with the results predicted by currently available methods such as Hyperbolic method, Asaoka's method, Hoshino's method and ${\sqrt{S}}$ method. All methods were found to have their own inherent error to predict final consolidation settlement. From results of analyzing the self-weight consolidation with time by using those methods, Asaoka's method predicted the best. Hyperbolic method predicted relatively well in error range of 2~24% for the case of showing the linearity in the relationship between T vs T/S in the stage of consolidation degree of 60~90 %. For the case of relation curve of T vs $T/S^2$ showing the lineality after the middle stage, error range from Hoshino method was close to those from Hyperbolic method. However, Hoshino method is not able to predict the final settlement in the case of relation curve of T vs $T/S^2$ being horizontal. For the given data about self-weight consolidation after the middle stage, relation curve of T vs T/S from ${\sqrt{S}}$ method shows the better linearity than that of T vs $T/{\sqrt{s}}$ from Hyperbolic method.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.95-105
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• 2004

This paper is an experimental and numerical research works about the effects of the b earing capacity of sloped rubble mound on the density of rubble mound and the position of footing. Centrifuge model tests were performed to investigate the bearing capacity of rubble m ound by changing the density of rubble mound and the location of loading in forms of s trip loading to simulate the caisson. Materials of rubble mound used in the model tests were crushed rocks having similar value of uniformity coefficient to the value in field. Two different relative densities of 80% and 90% were prepared during tests. The dimens ions of centrifuge model were trapezoidal shape of model mound having the bottom wid th of mound, 30cm and height of mound, 10cm. Gravity level applied during the centrif uge test was 50G. Surcharge loading in the forms of strip loading was applied on the t op of the sloped model mound. Tests were carried out by changing the position of loadi ng. The rigid model footing was located in the center of top of the model rubble mound and the edge of model footing was at the crest of mound. Test results were analyzed by using the limit equilibrium methods proposed by Meyer hof(1957) and Bowles(1982) and the numerical approach with FLAC being available com mercially software. For the numerical estimations with FLAC, the rubble mound was si mulated with the constitutive relationship of Mohr-Coulomb elasto-plastic model.

• Journal of the Korean Geotechnical Society
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• v.32 no.2
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• pp.43-52
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• 2016

Assembled Earth Retaining wall (AER-wall is used here) using back pile (back supporting beam is used from here) has been developed at Pusan National University. Both cost and time have been significantly reduced because AER-wall can be fabricated in a shop. Also its stability has been improved with a back supporting beam reducing earth pressure. In this study, the test results were analyzed after laboratory model tests were performed. The lateral displacement of AER-wall significantly decreased with both inclined wall and back supporting beams. As a result, the stability of AER-wall and effect of back supporting beam have been analyzed and verified.

• Journal of the Korean GEO-environmental Society
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• v.7 no.5
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• pp.41-48
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• 2006

Crib wall is one of the segmental grid retaining walls using headers and stretchers to establish the framework of the wall. In this method, grids formed by the intersection of headers and stretchers are generally filled with the gravel to maintain the weight of the wall. Therefore, the construction can be carried out with higher speed and much economically when compared with the concrete retaining wall. Furthermore, it has high drain capacity, and environmentally friendly aspects also have been pointed out because the possibility of the planting at the front of the wall. However, in the crib wall method, the relative movement between the individual headers and stretchers was generally recognized, and stress redistribution in the gravel filling was also observed when subjected to the external loading and self-weight of filling. Therefore, it has been thought that the distribution of the earth pressure in the crib wall system differ from that of the concrete retaining wall. In this study, the surcharge tests using the scaled model crib wall was carried out to observe the distribution of the earth pressure in the segmental grid retaining wall. The earth pressure was measured in the six specified height of wall, and the distribution of the pressure was analyzed. Furthermore, the earth pressure by computation or by the test using the concrete retaining wall was also considered to make comparison.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.21-29
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• 2003

In this study, practical guidelines to check the possibility of some lateral movement of piled abutment were investigated. In these tests, both the depth of soft clay and the rate of embankment construction are chosen to examine the effect on lateral soil movements. The depth of soft clay layer varies from 5.2 m to 11.6 m, and the rate of embankment construction has two types : staged construction(1m/30days, 1m/15days) and instant construction. Various measuring instruments such as LVDTs, strain gauges, pressure cells, and pore pressure transducers are installed in designed positions in ordo. to clarify the soil - pile interaction and the short and long term behavior f3. piled bridge abutments adjacent to surcharge loads. The validity of the proposed guidelines by centrifuge test was compared with the observed performance by lateral movement index, F(Japan Highway Public Corporation) and modified I index(Korea Highway Corporation). Based on the results obtained, the critical values off and modified I, as a practical guidelines, are proposed as 0.03 and 2.0, respectively.

• Korea Journal of Hospital Management
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• v.23 no.1
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• pp.51-64
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• 2018

Purposes : In February 2014, the government said that the National Health Insurance Service (NHIS) will enforce plan for reducing the financial burden from two major non-covered services including physician surcharges and private room charges, the main causes to increase uninsured, by 2017. The purpose of this study is to analyze the policy effect that performed so far by comparing out-of-pocket payment rates of policy process Methodology: This study analyzed admission medical expenses that occurred from January 2013 to March 2016 at a upper grade general hospitals in Daejeon. Number of study subjects were 134,924 and the data were analyzed with SPSS 22.0 program by using frequency, percentage, mean, standard deviation, ANOVA. The effect of two major non-payment improvement plan on out-of-pocket rates was ascertained via generalized estimating equation. Findings: Out-of-pocket payment rates was statistically significantly declined 2.7 percent than enforcement ago. Also, out-of-pocket payment, physician surcharge, the proportion of out-of-pocket payment of hospital room charge to out-of-pocket payment was statistically significantly declined. However, a further analysis of the cause of the decline in total medical costs is needed. Practical Implications: Physician surcharges and private room charges improvement policy had a positive effect on the decline of out-of-pocket payment rate. The policy of physician surcharges was very effective after the first policy enforcement but it was less effective to medical aids and near poor that was a more greater coverage than national health insurance. Since the policy has not been finalized, we have to continue a research for the successful implementation of the policy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.235-244
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• 1993

The present study was made based on the zero extension line theory and the well-known Mononobe-Okabe's to determine the dynamic earth pressures acting on the retaining walls. The zero extension line theory, which was proposed by Roscoe et al., assumes the coincidence between the loci of failure and the zero extension lines in soil mass. ln order to compute the dynamic earth pressure developed by an earthquake, it was assumed that for the vertical retaining walls with no surcharge, the backfill materials are dense and cohesionless sandy soils, there are no changes in soil parameters during earthquake, and the horizontal earthquake intensity is considered. The effects of horizontal earthquake intensity, internal friction angle of soil, wall friction angle and dilation angle, on the earth pressure coefficients were analysed. Final1y, the presented theories were successfully compared with the Mononobe-Okabe's as well.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.223-233
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• 2003

Sand compaction pile (SCP) is one of the ground improvement techniques which are being used for not only accelerating consolidation but also increasing bearing capacity of loose sands or soft clay grounds. In this study, laboratory model tests and 3-D finite element analyses were performed to investigate the interaction between sand compaction piles and surrounding soft soils. Based on the results obtained, as the area replacement ratio increases, the stress concentration ratio increases at the pile point, the settlement decreases, and the relative displacement between column and soil also decreases. It is also found that numerical study is illustrated by good comparison with model test results, and the numerical analysis revealed slip effects which could not be specifically identified in the model tests.