• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6A
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• pp.597-605
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• 2009

The safety of expressway bridges was estimated by checking the external condition rank based on the nondestructive inspection and material test and by measuring load carrying capacity based on the result of load test. Although the load carrying capacity of the bridges was clearly low compared to the design standard, it was examined that many of the bridges have good external condition rank relatively. Also, it can be assured that load carrying capacity shows a considerable difference according to various condition even though the bridges have similar construction year and a structural type. Therefore, this study showed various problems of the current safety measurement of expressway bridges by considering the status of the expressway bridges, external condition rank, and method of safety diagnosis and repair, rehabilitation for maintenance. Based on the existing data of over 400 expressway bridges, the load carrying capacity was analyzed quantitatively considering bridge type, serviced life, design live load, external condition rank and traffic count as variables. The result of this study will be expected to provide the basic information for a reasonable safety assessment of expressway bridge.

• Computational Structural Engineering
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• v.10 no.3
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• pp.133-143
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• 1997

In Korea, the construction of the first high-speed railroad on the Seoul-Pusan Corridor has already started 3 years ago, in the paper, an attempt is made to develop reliability-based safety and capacity evaluation models for the computer-aided maintenance of the high-speed railroad bridges. The strength limit state models of PC railroad bridges for reliability analysis encompass both the single failure mode such as bending or shear strength and the combined interaction equations which simultaneously take into account flexures, shear and torsion. Then, the actual load carrying capacity and the realistic safety of bridges are evaluated using the system reliability-based equivalent strength, and the results are compared with those of the element reliability based or conventional methods. It is concluded that the proposed models may be appropriately applied in practice for the realistic assessment of safety and capacity of high-speed railroad bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.51-58
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• 2021

As vertical extension remodeling policy was implemented in 2014, Safety Inspection Manual was established to ensure structural safety during the vertical extension remodeling. In the manual, the story weight for capability evaluation was based on the Safety Inspection Manual for Reconstruction. Although capability evaluation in the vertical extension remodeling is more important than reconstruction, engineering basis for the story weight is insufficient. Therefore it is necessary to improve the method of calculating the story weight. In this study, story importance and story weight were defined through the case analysis of capability evaluation in order to provide engineering basis for story weight. Also, new story weight equation was presented considering the load-bearing ratio of structural members.

• Geotechnical Engineering
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• v.8 no.4
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• pp.31-40
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• 1992

The arch of an ancient stone arch bridge consists of blocky stone blocks. For the purpose of estimation of load carrying capacity of a stone bridge, the mechanically frail discontinuities between stone blocks should be taken account of. Since the current way of analysis regards the stone arch as a continuous member, the characteristic of discontinuties is not considered. In this paper, an ancient stone arch bridge is analyzed and load carrying capacity is estimated by Finite Element Method with the discontinuties between blocks being modelled as interface elements. From the result of the study, it is shown that the load carrying capacity of a stone arch bridge is dependent of friction angle and shear stiffness between arch blocks rather than compressive strength of arch block itself and the stone arch bridge of granite is more influenced by shear stiffness than friction angle. The load carrying capacity of HONG bridge of HEUNG GUK temple analyzed in this paper is estimated as that of a third grade bridge.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.166-169
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• 2011

현재 국내에서 사용하고 있는 교량구조물의 성능평가방법으로는 크게 공용하중에 대한 내하율을 구하기 위하여 허용응력개념이나 강도설계 개념을 적용한 내하력 평가 기법이 사용되고 있다. 그러나 위의 방법들은 일반적으로 공용연수의 경과에 따른 재료 및 구조적 성능의 손실과 여러 가지 하중 및 환경적 요인들의 불확실성으로 인하여 발생하는 손상 및 열화를 반영하기 어렵다. 그리고 제원 및 재료물성치의 불확실성에 대한 기존 설계 자료의 DB 부족으로 기존의 평가방법에서는 이러한 시간의 경과에 따른 성능저하를 정확히 산정할 수 없어 이론상의 값과 실제 구조물과의 차이로 인한 불확실성이 존재 한다. 이에 본 연구에서는 공용년수 경과에 따른 시설물의 재료 구조적인 성능 및 거동분석 수행, 신뢰성 해석 수행을 바탕으로 교량 안전성 평가의 합리성 및 현실성을 제고하며, 구조 신뢰성 해석을 수행함으로써 실제 구조물의 강도 한계상태에 대한 파괴확률을 산정하고 그에 대응하는 위험도를 평가함으로써 안전성 검토를 수행하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.64-71
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• 2020

In recent years, many infrastructure have been rapidly aging around the world, which grows interest in the maintenance of the infrastructure. Among the social infrastructure, bridge is a very important structure to transport lots of human and various products. The performance evaluation of bridge can be divided into the condition evaluation and safety evaluation, proposed by Korea Infrastructure Safety and Technology Corporation. However, there are no separate criteria for the performance evaluation of three-class bridges. In general, the performance of bridge is dominated by the results of the condition evaluation, which is lower than that of the safety evaluation. Therefore, this study assessed the correlation between the condition evaluation of superstructure and bridge and also between the condition evaluation and the safety and load-carrying capacity of bridge. The results of the study would provide a basic data for the more quantitative and higher relevant performance evaluation of the existing bridges, particularly for three-class bridges.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.477-492
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• 2001

About half of bridges in United States are considered to be deficient and therefore are in need of repair or replacement. Half of these are functionally obsolete, and others do not have required strength For these bridges repairs and replacements are needed To avoid the high cost of rehabilitation the bridge rating must corectly report the present load-carrying capacity Rating engineers use Allowable Stress Design(ASD) Load Factor Design(LFD), and Load Resistance Factor Design(LRFD) to evaluate the bridge load carrying capacity In this paper the load rating methods are introduced and bridge load test data are collected. The reasons that make the difference between test results and analytical results are explained for each bridge load test And load rating methods are applied to real bridge. The rating factors from each method are compared.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.97-102
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• 2018

Conventional PSC I type girders were adversely affected by the self - weight of concrete, anchorage, prestressing. In order to overcome this problem, PSC girder was constructed with a hollow in the web and developed a hollow web PSC type I girder which is applicable to 50 - 70m span by multistage stressing and then actually long span hollow web PSC girder bridge was constructed. In this study, the results of Static Load Test and the Finite Element Analysis of the hollow web PSC I girder bridges were compared and analyzed, and the Load Carrying Capacity and safety of PSC girder bridges were evaluated. The Static Load Test and the numerical analysis results of this bridge showed similar tendency and the behavior of the hollow web PSC I girder was well simulated. The entire girders of the bridges had sufficient Load Carrying Capacity under the live load design condition and the bridges satisfied the safety and confirmed the appropriateness of the construction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.1-9
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• 2006

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted annual frequency of bridge collapse, AF, from the ship collision risk assessment is compared to an acceptance criterion. The analysis procedure is an iterative process in which a trial impact resistance is selected for a bridge component and a computed AF is compared to the acceptance criterion, and revisions to the analysis variables are made as necessary to achieve compliance. The distribution of the AF acceptance criterion among the exposed piers is generally based on the designer's judgment. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. To determine the design impact lateral resistance of bridge components such pylon and pier, the numerical analysis is performed iteratively with the analysis variable of impact resistance ratio of pylon to pier. The design impact lateral resistance can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics. More researches on the allocation model of AF and the determination of impact resistance are required.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2005.04a
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• pp.118-123
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• 2005