• 한국철도학회논문집
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• 제10권3호
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• pp.355-364
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• 2007

Recently a concrete slab tracks are being constructed on roadbed in the Gyoeng-bu 2nd phase high speed railways. In respdnding to this trend, new design standards and track materials maintenance systems, based on the slab track material safety and usage perspective, are needed. This research provides a roadbed design criteria and the maintenance system. The proposed roadbed design criteria and the maintenance system are based on the developed analysis meathod of train/slab-track interaction. where the roadbed settlement and train speed are utilized as mediating variables. In the analysis, the dynamic response of train/slab-track interaction apply to various speeds and settlements. the roadbed settlement is shown in a sinusoidal shape of wave, the scope of the settlement occurrence presented in its wavelengths, include 6meters, 10meters, 15merwes, 20meters, 30meters. The train speeds involved are 50, 100, 150, 200, 250, 300, 350, 400kilometers per hour.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.9-16
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• 2005

The purpose of this study is to investigate the settlement characteristics of large drilled shafts embedded into bed rocks. To perform this research, 35 pile load test results for the large drilled shafts are used, because these deep foundations generally used as substructure systems for grand bridges. In case of the yield load can not be easily determined by load(P)-settlement(S) curve from the pile load test at the maximum loads, the standard settlements which can determine a yield load is established. The residual settlement equation of pile embedded in gneiss and igneous rocks is presented in this study. Also a equation is proposed to characterize the relationship between loads and elastic settlements in pile load tests on the large drilled shaft embedded into bedrock. Then, large drilled shaft's settlement characteristics are examined on pile length, pile diameter and pile's socked depth into rock at the pile tip.

• Coupled systems mechanics
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• 제11권2호
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• pp.93-106
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• 2022

The total embankment settlement consists of three stages: the initial settlement, the primary consolidation settlement, and the secondary consolidation settlement. The total embankment settlement is largely controlled by the primary consolidation settlement, which is usually computed with numerical models that implement Biot's theory of consolidation. The key parameter that affects the primary consolidation time is the coefficient of permeability. Due to the complex stress and strain states in the foundation soil under the embankment, to be able to predict the consolidation time more precisely, aside from porosity-dependency, the strain-dependency of the coefficient of permeability should be also taken into account in numerical analyses. In this paper, we propose a two-dimensional plane strain numerical model of embankment primary consolidation, which implements Biot's theory of consolidation with both porosity-dependent and strain-dependent coefficient of permeability. We perform several numerical simulations. First, we demonstrate the influence of the strain-dependent coefficient of permeability on the computed results. Next, we validate our numerical model by comparing computed results against in-situ measurements for two road embankments: one near the city of Saga, and the other near the city of Boston. Finally, we give our concluding remarks.

• 한국지반공학회논문집
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• 제37권8호
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• pp.15-24
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• 2021

오늘날 도시 과밀화로 인해 한정된 부지를 효과적으로 사용하기 위해 기존 구조물과 인접한 조건에서 신규 구조물이 시공되는 경우가 많아지고 있다. 기존 구조물 근처에 신규 구조물이 시공되는 경우 기존 구조물에 의한 간섭효과가 발생할 수 있어, 이와 관련된 다양한 국내외 연구들이 진행되고 있지만 실험실 규모에서 모사할 수 있는 근접 구조물의 조건들이 한정적이라 실제 현장 조건을 제대로 반영하지 못하고 있다. 아울러 근접시공에 관한 명확한 기준과 역학적 거동이 규명되어 있지 않아 연구가 필요한 실정이다. 따라서 본 연구에서는 다양한 크기의 근접 구조물 시공 조건에 대한 지지력 및 침하량 변화를 관찰하기 위한 실험 연구를 수행하였다. 실험 결과 사질토 지반에서 구조물이 특정 거리 내에 근접 시공되는 경우 간섭효과로 인해 신규 구조물의 지지력 상승 효과가 확인되었으나 기존 구조물의 침하량이 증가하여 실제 근접 시공 시 면밀한 검토가 필요함을 확인하였다.

• 무역상무연구
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• 제67권
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• pp.69-95
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• 2015

The main purpose of this study is to analyse what are the key financial innovations in the euro area electronic payment systems. TARGET2 is the RTGS-system provided through the Eurosystem. It is used for settling central bank operations, for large interbank transfers in euro and also for other euro-denominated transfers. The specific features of TARGET2 include processing in real time, settlement in central bank money and immediate finality. In addition, the SEPA is a payment-integration initiative of the European Union for simplification of bank transfers denominated in euro. In particular, the main innovations consist of the completion of the phased migration to the TARGET2 infrastructure, and the introduction of a single retail payment market in euro - the SEPA and its products, schemes and frameworks. As the study analyse, the key innovations consist of the TARGET2 introduction, SEPA establishment and migration towards the T2S system. These innovations will lead to a better understanding of the payment and settlement systems' behavior in stress situations and to enhance the stability of the euro area financial system. Moreover, the successful integration of the European payment and settlement infrastructures will further contribute to the integration of the European financial markets, as well as to their higher competitiveness.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1212-1217
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• 2008

In this study, in order to clarify the effect of the direction of cyclic shear on the post-earthquake settlement the multi-directional shear tests were carried out for Toyoura Japan standard sand, Genkai natural sand and the Granulated Blast Furnace Slag (GBFS). In a series of tests, number of strain cycles was changed as n=5-200 and the shear strain amplitude varied from 0.1% to 1.0%. The relative density was also changed as Dr=50, 60 and 70%. From the test results for Toyoura sand and GBFS, it is clarified that the post cyclic settlement is relatively large at the small relative density and becomes large with the shear strain amplitude. When the influence of the direction of cyclic shear is decreases, the post cyclic settlement strain for Toyoura sand is converged to a constant value, but the GBFS is increased with the number of strain cycles.

• 디지털융복합연구
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• 제11권11호
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• pp.29-36
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• 2013

전자상거래 시장이 삐르게 증가하고 관련 산업이 발달하고 있다. 전자상거래의 특징인 비대면 거래 방식규모의 증가와 더불어 다양한 결제수단 등장으로 전자상거래에서 소비자 피해도 증가하고 있는 추세이다. 본 연구는 구매안전서비스라는 제도측면에서 소비자 보호방안에 대하여 살펴보았다. 구매안전서비스의 대표적인 결제대금예치 제도와 소비자피해보상보험 등의 한계점을 살펴보고 개선방안을 제시하였다. 불법적인 구매안전서비스 홍보를 방지하기 위해서는 소비자의 포상신고제를 운영하고 결제대금예치제도의 예치기간 악용에 대해서는 차감정산제도와 결제 대금예치사업자에게 분쟁중재역할 제공에 대한 검토가 필요하다. 결제대금예치를 통한 거래발생시 증서형태로 소비자에게 전달하고 구매안전서비스의 적극적인 홍보와 지속적인 제도개선 노력이 필요하다.

• Geomechanics and Engineering
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• 제34권6호
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• pp.649-664
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• 2023

Structural inertial interaction is a representative the effect of dynamic soil-foundation-structure interaction (SFSI), which leads to a relative displacement between soil and foundation, period lengthening, and damping increasing phenomena. However, for a system with a significantly heavy foundation, the dynamic inertia of the foundation influences and interacts with the structural seismic response. The structure-to-foundation mass ratio (MR) quantifies the distribution of mass between the structure and foundation for a structure on a shallow foundation. Although both systems exhibit the same vertical factor of safety (FS_v), the MR and corresponding seismic responses attributed to the structure and foundation masses may differ. This study explored the influence of MR on the permanent deformation and seismic response of soil-foundation-structure system considering SFSI via numerical simulations. Given that numerous dimensionless parameters of SFSI described its influence on the structural seismic response, the parameters, except for MR and FS_v, were fixed for the sensitivity analysis. The results demonstrated that the foundation inertia of heavier foundations induced more settlement due to sliding behavior of heavily-loaded systems. Moreover, the structural inertia of heavier structures evidently exhibited foundation rocking behavior, which results in a more elongated natural period of the structure for lightly-loaded systems.

• Journal of Information Processing Systems
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• 제16권2호
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• pp.318-328
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• 2020

Letter of Credit (L/C) is currently a very popular international settlement method frequently used in international trade processes amongst countries around the globe. Compared with other international settlement methods, however, L/C has some obvious shortcomings. Firstly, it is not easy to use due to the sophisticated processes its usage involves. Secondly, it is sometimes accompanied by a few risks and some uncertainty. Thus, highly efficient methods need to be used to assess and control these risks. To begin with, FAHP and KMV methods are used to resolve the problem of incomplete information associated with L/C and then, on this basis, Bayesian game theory is used in order to make more scientific and reasonable decisions with respect to international trade.

• Smart Structures and Systems
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• 제25권4호
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• pp.433-446
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• 2020

In this paper the effect of confining pressure and tunnel depth on the ground vertical settlement has been investigated using particle flow code (PFC2D). For this perpuse firstly calibration of PFC2D was performed using both of tensile test and triaxial test. Then a model with dimention of 100 m × 100 m was built. A circular tunnel with diameter of 20 m was drillled in the middle of the model. Also, a rectangular tunnel with wide of 10 m and length of 20 m was drilled in the model. The center of tunnel was situated 15 m, 20 m, 25 m, 30 m, 35 m, 40 m, 45 m, 50 m, 55 m and 60 m below the ground surface. these models are under confining pressure of 0.001 GPa, 0.005 GPa, 0.01 GPa, 0.03 GPa, 0.05 GPa and 0.07 GPa. The results show that the volume of colapce zone is constant by increasing the distance between ground surface and tunnel position. Also, the volume of colapce zone was increased by decreasing of confining pressure. The maximum of settlement occurs at the top of the tunnel roof. The maximum of settlement occurs when center of tunnel was situated 15 m below the ground surface. The settlement decreases by increasing the distance between tunnel center line and measuring circles in the ground surface. The minimum of settlement occurs when center of circular tunnel was situated 60 m below the surface ground. Its to be note that the settlement increase by decreasing the confining pressure.