• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.3
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• pp.179-186
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• 2021

In general, the daily safety inspection activities, which investigate damages in structures and measures the size of the damage, have been relied heavily on the visual inspection so far. Since the probe of the condition and performance of facilities by such personnel is often dependent on the subjective judgment of the investigator, the consistency and repeatability of the probing results may reduce. Particularly, damage located in a difficult-to-reach place depends mainly on experience with the naked eye, and an unsafe method using a ladder has mainly applied when necessary. Therefore, in this study, we tried to propose a way of using images that can reduce the deviation between safety inspection investigators, enhance objectivity, and improve the safety of workers. In this study, we have applied homographic transformation as a method of correcting the image. As a result of analyzing the size of the damage in the corrected image of the test subject, it confirms that the accuracy of measuring the magnitude of the damage can satisfy the target levels of 5.0mm and 0.005m², the target accuracy levels. As a result of the field verification test to which the proposed image correction technique applied, the coefficient of variation of the crack length in the structure decreased from 5.4~7.0% to 0.072~0.12%, and that of the damaged area from 10.9% to 1.6%. It confirms that the measurement accuracy is improved. Therefore, it is expected that this study on the image utilization technique in safety inspection activities can increase the accuracy of damage measurement and improve the reliability of the safety inspection reports and exterior survey drawings.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.33-44
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• 2004

This paper is focused on the spatial variability of measured strong motion data during earthquake and its relationship with the performance of water distribution pipelines and residential buildings. Analyses of strong motion and the correlations of peak ground velocity (PGV) and pipeline and building damage were conducted with a very large geographical information system (GIS) database including the relationship of time and earthquake intensity and the measured location, and Kriging spatial statistics. Kriging was used to develop regressions of pipeline repair rate (RR) and residential building damage ratio (DR) associated with $90\%$ confidence peak ground velocity (PGV). Such regressions using Kriging provide an explicit means of characterizing the uncertainty embodied in the strong motion data compared with other spacial statistics such as inverse distance method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.4
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• pp.577-585
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• 2024

Infrastructure plays a crucial role in the industrial development and economic growth of a nation. However, recently, domestic infrastructure has been causing not only safety risks due to aging but also social and economic inefficiencies, increasing the need for maintenance. In particular, the deterioration rate of bridges is serious, so application of appropriate repair and rehabilitation methods and estimation of its quantity are required. In this study, frequently applied repair methods for bridges using data from the Facility Integrated Management System (FMS) were identified. the empirical correlation between damage volume and the repair volume was analyzed using Bridge Management System (BMS) data. The result of the analysis showed that the ratio of the repair volume to the damage volume was 1.0. The guideline, on the other hand, suggest 1.5 the ratio of the repair volume to the damage volume. Although the guidelines differently present more conservative figures considering safety, this study is significant in that it presents a practical ratio through data analysis results. This results can be used to develop a model that can calculate the amount of repair and rehabilitation of various facilities in the future.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.6
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• pp.153-161
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• 2013

This paper provides core standardization items and method for the building information modeling (BIM) based maintenance and management (M&M) of civil infrastructure. Value chain of the M&M and characteristics of BIM technology has been analyzed and compared. As a result, it has been revealed that the initial activity recording damage information is very similar to the BIM-based information operation. The core standardization items for generation and operation of BIM data were identified according to the M&M value chain, The identified items were categorized into common standard item and specialized items for M&M of civil infrastructure, and proper government funded organizations for each standardization items were introduced on the basis of the roles in the laws.

• Magazine of the Korean Society of Hazard Mitigation
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• v.11 no.1
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• pp.95-98
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• 2011

최근 국내에서 사회기반시설물에 대한 안전관리 네트워크 통합시스템 구축을 위한 국가핵심과제가 진행되고 있다. 본 연구에서는, 위 과제의 일환으로 진행 중인 철도교량의 구조건전성 모니터링 시스템 구축 및 운용에 대하여 기술하였다. 효율적인 철도교량 모니터링 시스템 구축을 위하여 다양한 종류의 스마트센서가 적용되었으며, 웹 기반의 네트워킹을 통해 외부에서 모니터링 시스템을 원격으로 접속, 제어 할 수 있도록 하였다. 철도교량의 국부 손상을 모니터링 하기 위해 압전센서를 활용한 무선 임피던스 노드를 적용하였고, 구조물 전체의 거동 분석을 위하여 가속도 센서 및 광섬유 센서를 적용하였다. 구조물의 장기 계측을 통한 철도 주행 및 외부 환경에 따른 거동 분석을 수행하였으며, 손상 평가를 위한 신호처리 알고리즘이 적용되었다.

• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.35-43
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• 2015

In this study, The failure of water supply facilities is categorized into two phases: functional failure and complete collapse. The fragility curve of water supply facilities under PGA has been developed for two loading cases: actual overseas earthquake and Korean artificial earthquake. The seismic fragility of water supply facilities has been analyzed and compared about failure phases and PGA. From the analysis results, the probability of failure of the wrapped steel pipe and ductile case iron pipe under Korean artificial earthquake has been shown as lower than that under actual overseas earthquake in the range from 0.1 to 0.4. The suggested seismic fragility curve by using Korean artificial earthquake can be exploited in a reasonable seismic design reflecting Korean local ground condition.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.107-113
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• 2008

As it recently appears that LCC (Life Cycle Cost) analysis may be considered as an essential method for economic evaluation of infrastructures. Many researches have been made to assess LCC of each facility based on reasonable methods. However, expected maintenance repair cost must be reasonably estimated to enhance the reliability of LCC analysis through systematic and rational methods. This study is intended to propose a rational approach to reliability-based LCC analysis of high-speed railway steel bridges considering lifetime corrosion and fatigue damage. However in Korea, since high speed railway steel bridges are only recently constructed, no direct statistical data are available for the account of the maintenance cost and thus their maintenance characteristics are not clear yet. In this paper, for the assessment of expected maintenance/repair cost, the fatigue system reliability analysis incorporating the corrosion effect is proposed by considering the corrosion and fatigue damage using measured data of high speed railway steel bridges. A model proposed by Rahgozar, of at for fatigue notch factor considering the corrosion effect is used in order to incorporate the corrosion effect into the fatigue strength reduction and S-N curve. Finally, the effectiveness of LCC model proposed for high-speed railway steel bridges is demonstrated by a numerical example.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.284-289
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• 2016

In recent years, the earthquake sequence in Christchurch, New Zealand (NZ) was unprecedented in terms of repeated earthquake shocks with substantial levels of ground motion affecting modern infrastructure, and in particular, broad and precise reports for liquefaction-induced permanent ground deformation (PGD) and repairs of wastewater (WW) pipelines were collected. In this study, a geographical information system (GIS) and linear regression analysis were performed using data for the length and repair points of earthenware (EW) and concrete (CONC) wastewater pipelines acquired after the MW 6.2 February 22, 2011 earthquake. The repair rates (repairs/km) for the EW and CONC wastewater pipelines were evaluated inside the areas of PGD, and both angular distortion of ground and lateral ground strain were calculated from the high resolution LiDAR data acquired before and after the seismic event. The research results showed that both pipelines have similar trends of damage but the CONC wastewater pipeline with higher stiffness showed less damage. The results of linear regression analyses can be used to predict the repair rates for EW and CONC wastewater pipelines inside the areas of PGD induced by future earthquakes.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.1031-1036
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• 2000

지리정보시스템(Geographic Information System)분야에서 사회 기반 시설에 대한 요구가 증대되고, 시설물을 관리하기 위한 지리정보 데이터 베이스 구축이 필요하며, 데이터베이스 구축을 위해서는 지도 정보를 필요로 한다. 본 논문에서는 지도 정보를 자동으로 분석하여 등고선과 숫자, 기호를 추출해 내는 알고리즘에 대해 연구하였다. 지도상의 숫자, 기호를 추출하고 효율적으로 분류하기 위해 불필요한 자료를 제거하고 필요한 정보를 추출한 후 손상된 부분을 복원하는 방법과 필요한 정보만을 추출한 후 손상된 부분을 복원하는 방법을 제안하고 결과를 비교하였다. 이렇게 추출한 정보가 의미를 갖는 단위(기호, 숫자)들로 분류되도록 라벨링 방법과 무게 중심을 이용한 물체 추출 방법을 적용하여 숫자 기호들을 자동으로 분류하였으며, 여러 지역의 지형도를 입력하여 모의실험을 통해 제안한 알고리즘의 효율성을 증명하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.1-8
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• 2020

Recent the number, size and accident on Youth Training Facility have increased annually. Also, the discussion and interest relation to safety and maintenance of youth culture and education. This study asserts the necessity and importance of present condition and characteristic based on Youth Training Facility in domestic. Therefore, Results of this study, it is appeared that very vulnerable to improve safety and maintenance in them. Accordingly, The purpose of this study is to investigate the current status for the whole youth facilities. second it estimate on main damage and defect of them for the period four years.