• Title/Summary/Keyword: 도로교

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Study on the Reinforced Concrete Slab Bridges of North Korea (북한의 철근콘크리트 슬래브교에 관한 연구)

  • Han, Eui Seok;Lee, In Keun;Park, Sun Kyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.455-464
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    • 2013
  • If North Korea continuously remains an isolated nation without social interaction with South Korea, the gaps in the theoretical and technological status in construction technology become greater between North and South Korea. Therefore if interactions between North and South Korea can be made, there will be significant improvement in infrastructure technological performance can be made(i.e., Reinforced Concrete bridges). This study was performed to compare and analyze data related to the design standards of North Korean RC bridges and to execute a structural analysis based on standard design specifications of RC slab bridges. Especially, basic study of analyzing the influences on design truck loads of North and South Korea was conducted for the purpose of predicting the performance of North Korean RC slab bridges and the safety levels of traveling vehicles in advance. It is expected that the results of this study can be used as fundamental data for the set-up of South-North RC bridge specification when South and North Korea enter a stage of cooperation and interaction between South and North Korea are actively pursued to prepare for reunification.

Simulation Technique for Estimation of Extreme Traffic Load Effects on Bridges (도로교 최대차량하중효과 분석을 위한 모의해석기법)

  • Hwang, Hak Joo;Kim, Sang Hyo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.4
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    • pp.77-86
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    • 1993
  • Recently it is reported in many countries that highway bridges are seriously damaged due to increasing volume of overloaded heavy vehicles. The safety of bridges are highly related to the design load level and the characteristics of extreme load effect induced by traffic loads during its lifetime. The maximum structural load effect during lifetime may be produced by simultaneous loading of trucks with moderate weights on a bridge rather than by single loading of extremely heavy trucks. In this study, a simulation technique to estimate extreme load effect due to traffic loadings has been developed, in which important characteristics of traffic loadings, such as heavy vehicle proportion, traffic mode, vehicle weights, headway distribution. daily traffic volume, etc., should be properly considered. In addition. sensitivity analysis on those factors have been performed.

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A Study on Bridge Live Loads and Traffic Modes (도로교 차량하중 및 통행특성에 관한 연구)

  • Kim, Sang Hyo;Park, Hung Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.4
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    • pp.107-116
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    • 1992
  • The structural integrity of bridges is mainly damaged by overloaded heavy vehicles. The increasing volumes of overloaded heavy vehicles has been indicated as serious state. As results several countries have revised their bridge load codes. However, because of variety of truck types and their weights it is difficult to develop rational standard truck loads. In addition the common practice that only one design configuration of standard truck is adopted to design variety of bridges causes further difficulties. The objective of the study is to investigate the statistical characteristics of vehicle loadings based on survey data collected, in which some major factors, such as vehicle configurations, vehicle weights, traffic modes, etc., are incorporated. The vehicle load effects due to single presence of heavy truck are also tested with several short-span bridges and probabilistic characteristics of current design practices are evaluated.

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A Proposal of Reference Power Spectral Density Functions Compatible with Highway Bridge Design Specta (도로교 내진설계 스펙트럼에 부합하는 표준 PSD함수의 제안)

  • Choi, Dong Ho;Lee, Sang Hoon;Koh, Jung Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1A
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    • pp.59-67
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    • 2008
  • Acceleration time history used in the seismic analysis of nuclear power plant structures should envelop a target power spectral density (PSD) function in addition to the design response spectrum in order to have sufficient energy at each frequency for the purpose of ensuring adequate load. The safety for complex long-span highway bridges cannot be over-emphasize. An alternative method to improve the seismic capacity is to ensure the minimum PSD function of the applied seismic load. This study proposes a technical scheme to obtain the reference power spectral density function by using artificial earthquakes which are compatible with the highway bridge design spectrum.

The Essence and Significance of the Concept of 'Return to the Former World' in Donghak-gyo (동학교 '도로 선천(先天)'사상의 내용과 의의)

  • Kim Tak
    • Journal of the Daesoon Academy of Sciences
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    • v.48
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    • pp.199-237
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    • 2024
  • Donghak-gyo, the Teaching of Eastern Learning, is a new religious order founded by Kim Ju-hee, centered around the Donghak (Eastern Learning) lineage. The core thought conveyed in the lyrics of Donghak-gyo songs (gasa) can be identified as the concept of 'Return to the Former World (先天),' considering the frequency of the term and the content of the recited verses. The view of time and destiny (時運觀) held by Eastern Learning emphasizes the concept of 'Another Great Opening.' Donghak-gyo's perspective on time and destiny is further rooted in the concept of 'Return to the Former World.' Donghak-gyo particularly emphasizes the term 'Former World,' and incorporates the Study of Changes (易學) into their songs. They recite verses that depict the situation of the Great Opening as an interaction between yin and yang. In Donghak-gyo, it is emphatically asserted that the completion of the Later World's destiny leads to the achievement of the 'Return to the Former World.' It is sung that with the restoration of destiny associated with the 'Return to the Former World,' the symbolic 'Spring (春)' represented by the virtue of Wood (木德) will return. Donghak-gyo describes the unfolding of a new cycle of destiny (運數) as the 'restoration of Changes (易).' When this occurs, they refer to the emerging new world, characterized by a new order and norms, as the 'Return to the Former World,' asserting that a 'moral world' will be established, leading to the development of a moral civilization. It is also sung that the restoration of the destiny associated with the Return to the Former World is akin to the restoration of the Heavenly Dao (天道). The characteristics of the concept of the Return to the Former World are threefold: firstly, it advocates a nostalgic system; secondly, it is a backward-looking thought; and thirdly, the idea of 'cyclical repetition' encourages tangible actions such as 'returning to the origin' or 'restoring fundamentals.' The concept of Return to the Former World in Donghak-gyo, unlike many new religions of those days, provided a unique conceptualization and understanding of the Former World and presented a new framework for interpretation. It moved away from the notion of discarding the Former World as a relic of an outdated era, and instead interpreted it as a new era to be embraced. Therefore, the concept of 'Return to the Former World' in Donghak-gyo should be re-assessed as one of the ideologies that inherits the pursuit of returning to and restoring the past in Eastern traditions. However, it can be criticized for lacking a concrete methodology with regards to the 'Return to the Former World.' Additionally, it is noted for deficiencies in ethical consciousness and moral virtues. Furthermore, its explanation about the Former World come across as insufficient. Thus, the concept of the 'Return to the Former World' in Donghak-gyo seems to be characterized more by declarative slogans than substantive content.

Evaluation of Proper Level of the Longitudinal Prestress for the Precast Deck of Railway Bridges Considering the Temperature Change (철도교용 프리케스트 바닥판의 온도변화를 고려한 적정한 종방향 프리스트레스 수준의 산정)

  • Jeon, Se Jin;Kim, Young Jin;Kim, Seong Woon;Kim, Cheol Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3D
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    • pp.499-509
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    • 2006
  • Precast concrete deck has many advantages comparing with the in-situ concrete deck, and has been successfully applied to replacement of the deteriorated decks and to the newly constructed highway bridges in domestic region. In order to apply the precast decks into the railway bridges, however, differences of the load characteristics between the highway and the railway should be properly taken into account including the train load, longitudinal force of the continuous welded rail, acceleration or braking force, temperature change and shrinkage. Proper level of the longitudinal prestress of the tendons that can ensure integrity of the transverse joints in the deck system is of a primary importance. To this aim, the longitudinal tensile stresses induced by the design loads are derived using three-dimensional finite element analyses for the frequently adopted PSC composite girder railway bridge. The effect of the temperature change is also investigated considering the design codes and theoretical equations in an in-depth manner. The estimated proper prestress level to counteract those tensile stresses is above 2.4 MPa, which is similar to the case of the highway bridges.

Dynamic Characteristics of a Cable-stayed Bridge Using Global Navigation Satellite System (GNSS를 이용한 사장교의 동특성 평가)

  • Park, Jong Chil;Gil, Heung Bae;Kang, Sang Gyu;Lim, Chae Woon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.4A
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    • pp.375-382
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    • 2010
  • This paper presents the extraction of natural frequencies and mode shapes of a cable-stayed bridge using data acquired from GNSS. The response signals of 6 GNSS measuring points installed at the Seohae cable-stayed bridge are used for analysis of dynamic characteristics. Using normalization process and a third order Butterworth filter for the measured signals, the related pass band's signals have been isolated. Then, the acceleration data by double differentiation for these signals are obtained. Total five natural frequencies have been extracted by the fast Fourier transform and compared to the results of different studies. For the acceleration obtained from GNSS signals, the mode shapes of the bridge have been successfully extracted by TDD technique.