• Title/Summary/Keyword: load-carrying capacity

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A Study on the Change of Load Carrying Capacity of High-tension Bolt Joints by Critical Sections (단면결손에 따른 고장력볼트 체결부의 내하력 변화에 관한 연구)

  • Park, Jeong-Ung;Yang, Seung-Hyun;Jang, Seok-In
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2402-2408
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    • 2009
  • This study conducted a static tensile test in order to prevent the lowering of load carrying capacity caused by critical sections made by over bolt holes in the base plate and the cover plate of steel member joints using high-tension bolts. The change of the load carrying capacity of joints was examined by comparison of the maximum load on joint fracture obtained from the tensile test with critical section rate and design strength. According to the results, the rate of decrease in strength was higher when the critical section rate was high, and in particular, decrease in strength was affected much more by critical sections in the base plate than by those in the cover plate. In high-tension bolt joints using over bolt holes for the base plate and the cover plate, load carrying performance was somewhat lower than that in joints using standard bolt holes, but the maximum tensile strength on facture was over 15% higher than design fracture strength. According to the results of this study, the use of over bolt holes in high-tension bolt joints had an insignificant effect on the lowering of load carrying capacity, so the allowance of over bolt holes in the joints of steel members is expected to enhance to the economy and efficiency of the works.

Evaluation of Shear Load Carrying Capacity of Lateral Supporting Concrete Block for Sliding Slab Track Considering Construction Joint (타설 경계면을 고려한 슬라이딩 궤도 횡방향 지지 콘크리트 블록의 전단 내하력 평가)

  • Lee, Seong-Cheol;Jang, Seung Yup;Lee, Kyoung-Chan
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.1
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    • pp.55-61
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    • 2017
  • Recently several researches have been conducted to develop sliding track system in which friction between concrete track and bridge slab has been reduced. This paper investigated shear load carrying capacity of lateral supporting concrete block which should be implemented to resist lateral load due to train in sliding track system. In order to evaluate shear load carrying capacity of lateral supporting concrete block, analytical model has been developed considering concrete friction and rebar dowel action along construction joint. The proposed model predicted test results on the shear load carrying capacity from literature conservatively by 13~23% because effect of aggregate interlock along crack surface was neglected. Since construction joint status is ambiguous on construction site, it can be concluded that the proposed model can be used for reasonable design of lateral supporting concrete block. Based on the proposed model, design proposal for lateral supporting concrete block has been established.

Reliability-Based Assessment of Safety and Load Carrying Capacity of Steel-Box Pedestrian Bridges (신뢰성에 기초한 강상형 보도육교의 안전도 및 내하력 평가)

  • 조효남;최영민;이은철
    • Computational Structural Engineering
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    • v.10 no.2
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    • pp.189-201
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    • 1997
  • A number of standard type of steel-box pedestrian bridges are constructed in th metropolitan high way or heavy traffic urban area. Although it has the advantage of speedy construction because of its simple structural form and prefabricated erection method, it has been reported that many of these bridges are deteriorated or damaged and thus are in the state such that it would give unsafe and uncomfortable feeling to pedestrians. In the paper, for the realistic assessment of safety and load carrying capacity of deteriorated and/or damaged steel box pedestrian bridges, an interactive non-linear limit state model is formulated based on the von Mises' combined stress yield criterion. It has been demonstrated that the proposed model is effective for the reliability-based safety assessment and load carrying capacity evaluation of steel-box pedestrian bridges. In addition, this study suggests an effective and practical field load test method for pedestrian bridges.

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Impact Factor Analysis of Response Adjustment Factor of PSC Composite Bridge Using Optical Fiber Sensor (광섬유 센서를 이용한 PSC 합성형교의 응답보정계수 영향인자 분석)

  • Kim, Ho Sun;Jang, Hwa Sup;Yang, Dong Woon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.1
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    • pp.35-43
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    • 2012
  • In general, load carrying capacity, one of the load & resistance capacities in bridges, has more margins than the load carrying capacity evaluated with theoretical methods, unless there are severe damages, defects or material deterioration phenomena that can have a great impact on the behavior of bridges. However, errors have been already included in the current processes of loading tests and structural analysis for measuring load carrying capacity, thus devaluing the reliability of response adjustment factor. Therefore, this study found out the problems of existing electric resistance strain and displacement sensors in sensor suite to solve the problems with sensors and the errors in the appropriateness of structural analysis model, thereby leading to the changes into an optical fiber smart sensor with excellent performance. Besides, the study attempted to ensure the accuracy of response adjustment factor by selecting the optimal models through the interpretation of various structural analysis models.

A Study on the Evaluation Methods of the Load-Carrying Capacity of PSC I Type Girder Considering Material Nonlinear (재료 비선형을 고려한 PSC I형 거더교의 내하력평가 기법에 관한 고찰)

  • 심종성;김규선;문도영;주민관
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.187-192
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    • 2003
  • Nowadays, It has adapted both Ultimate Strength Design(USD) and Allowable Stress Design(ASD) Method evaluating load-carrying capacity of PSC I Type Girder Bridge. But it has confused because the each method has brought some different results. This study shows some results of loading test of the PSC I type Girder Bridge and analyzed the structural behavior by FEM analysis considering material nonlinear. Parametric study of effective prestress of post tendon is performed and compared to results of loading test.

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A Safety Evaluation Strategy Employing Bridge Health Monitoring System by Traffic Loads (교량 상시계측시스템을 이용한 실시간 안전성평가시스템 구축 방안)

  • Lee, Woo-Sang;Joo, Bong-Chul;Park, Ki-Tae
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.481-484
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    • 2008
  • The research was carried out to suggest the bridge health monitoring systems that have been composed damage detection algorithm and a system for evaluation load carrying capacity of bridge by traffic loads for the purpose of safety management of bridge structure in efficient and economic.

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An Improved Method for the Evaluation of Load Carrying Capacity of Existing Bridges (교량 구조물의 개선된 내하력 평가기법)

  • Oh, Byung-Whan;Kim, Ki-Su;Shin, Ho-Song;Lee, Woong-Jong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.1 no.1
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    • pp.53-64
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    • 1997
  • Recently, safety evaluation of structures has received great concern in this country. One major problem in safety evaluation is that the results are often quite different depending upon evaluation authority. This is mainly due to arbitrary selection of various modification factors when employing allowable stress method for safety evaluation, The purpose of the present study is, therefore, to establish a rational method to determine the modification factors, especially the stress modification factor and the deterioration modification factor based on visual examination. It is thought that the proposed method yields a rational and consistent result for safety evaluation and may efficiently be used for realistic evaluation of load capacity of bridge structures.

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Analysis of Capacity Factors and Capacity Credits for Wind Turbines Installed in Korea (국내 풍력발전 설비의 이용률과 용량크레딧 분석)

  • Paik, Chunhyun
    • Journal of the Korean Solar Energy Society
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    • v.39 no.4
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    • pp.79-91
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    • 2019
  • The capacity credit (CC) is a key metric for mid- to long-term power system capacity planning. The purpose of this study is to estimate the CCs of domestic wind turbines. Based on hourly capacity factor (CF) data during the seven years from 2011 to 2017, the new so-called probabilistic CF scheme is introduced to effectively reflect the variability of CFs on CC estimation. The CCs are then estimated through the CF-based method and the ELCC (Effective Load Carrying Capability) method reflecting the probabilistic CF scheme, and the results are compared. The results show that the CC value 0.019 for domestic wind turbines proposed in the $8^{th}$ Basic Plan for Electricity Supply and Demand corresponds to the CC with a confidence level slightly lower than 95%.

Analysis of Load Carrying Capacity of Bridges Based on Field Data with Serviced Time (실측자료에 기초한 공용년수 증가에 따른 교량 내하력 분석)

  • Kyung, Kab Soo;Lee, Yeong Il;Lee, Sung Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.1
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    • pp.31-38
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    • 2015
  • In this paper, change of load carrying capacity of bridges with time was analyzed referring to the safety inspect data stored in the KISTEC. From this study, it was known that the capacity is rated differently by various parameters such as inspector's subjective. Accordingly, an improved method, in this paper, is suggested which can correct deviation due to several uncertainties involved in rating process. The suggested method can be utilized for efficient maintenance of bridges such as cycles and determination of priority of retrofit, and estimation of service life etc.

A numerical investigation of seismic performance of large span single-layer latticed domes with semi-rigid joints

  • Zhang, Huidong;Han, Qinghua
    • Structural Engineering and Mechanics
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    • v.48 no.1
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    • pp.57-75
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    • 2013
  • It is still inadequate for investigating the highly nonlinear and complex mechanical behaviors of single-layer latticed domes by only performing a force-based demand-capacity analysis. The energy-based balance method has been largely accepted for assessing the seismic performance of a structure in recent years. The various factors, such as span-to-rise ratio, joint rigidity and damping model, have a remarkable effect on the load-carrying capacity of a single-layer latticed dome. Therefore, it is necessary to determine the maximum load-carrying capacity of a dome under extreme loading conditions. In this paper, a mechanical model for members of the semi-rigidly jointed single-layer latticed domes, which combines fiber section model with semi-rigid connections, is proposed. The static load-carrying capacity and seismic performance on the single-layer latticed domes are evaluated by means of the mechanical model. In these analyses, different geometric parameters, joint rigidities and roof loads are discussed. The buckling behaviors of members and damage distribution of the structure are presented in detail. The sensitivity of dynamic demand parameters of the structures subjected to strong earthquakes to the damping is analyzed. The results are helpful to have a better understanding of the seismic performance of the single-layer latticed domes.