• Journal of Korean Tunnelling and Underground Space Association
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• v.3 no.4
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• pp.35-55
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• 2001

Recently, as tunnel structures are getting older and decrepit, many tunnel inspections are carried out for evaluating the tunnel state and safety. But, because there is no exact standard for tunnel state and safety, depending on subjective decision, the new standard to assess the tunnel state is required. The existing standard including mainly the assessment of the state of tunnel lining is not considered the characteristics of tunnel as underground structures. Also, the item of assessment and process of grading and classifying the state of tunnel is not objective and systemetic. In this study, new standard for assessment of tunnel state is presented for improving the problems in evaluating the tunnel state and safety. In the new standard, the new items of assessment including geotechnical condition were selected and graded, the process in classifying the tunnel state is quantitative for objective assessment for tunnel state. This new standard and method is practically used in effective safety inspection and diagnosis and tunnel maintenance.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.246-253
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• 2010

National major facilities have been rigorously investigated using regular safety inspections and precision safety diagnosis since the Special Law for Facilities Safety Management was made in 1995. However, the process of safety inspection and precision safety diagnosis could be doubted due to intervention of facility owner for safety level evaluation, competition to obtain low price order, and low technical skills of inspection companies. Although the management processes for evaluating the inspection companies were used for several years, the process should continue to improve in the safety inspection field. This study analyzed the recent evaluation system and the ratios of insufficient inspection. Estimation of national loss expenses to the insufficient safety inspection was investigated to recognize the necessity for the improvement of facility inspection process and evaluation system.

• Land and Housing Review
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• v.11 no.3
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• pp.83-92
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• 2020

In South Korea, problems caused by material deterioration of time-worn concrete structures have been increased recently. Because severe material deterioration could damage the structure's safety, it's important to evaluate the old structure's condition and structural capacity regularly to keep its proper performance. The safety evaluation of concrete structures has been initiated and performed periodically since 1995 according to a guideline in accordance with a law in Korea. The guideline prescribes the evaluation types, intervals and methods of the target structure. A lot of cost and labor have been invested every year to carry out the regular safety evaluation. However, it's not clear that the current manual could inspect the old structure's condition and assess the structural capacity precisely. Thus, the verification study initiated to figure out the Korean safety evaluation manual's practicalness. First, the Korean manual was analyzed and then compared with that of other countries for concrete bridges which are representative concrete structure. After that, the previously written evaluation reports were collected and analyzed to find out how the safety evaluation has been carried out. Based on the study results, the parts requiring verification of the manual were drawn. A research program is in progress in order to verify the parts by performing tests with actual structural members from decommissioned concrete bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.3
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• pp.225-233
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• 2004

In this study, the seismic safety of containment building is assessed using response surface method. The structural analyses considering random variables such as load, resistance and analysis by ABAQUS are performed to obtain the structural response. The structural response is represented by polynomial of random variables, and the reliability analysis is performed by Level II method. Drucker-Prager failure criterion is applied as limit state function to take bi-axial stress states into account in the concrete. The lifetime probability of failure is evaluated by considering the lifetime of containment building, the annual occurrence rate of earthquake and the conditional probability of failure. Also the sensitivity analysis on the selection of sampling points is performed to obtain the steady results from response surface method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.136-142
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• 2019

Nuclear power plant concrete structures are in contact with the coast, and durability due to chloride attack is very important because it is used as cooling water by taking seawater. For this purpose, a 3-year long-term saltwater immersion test was carried out to evaluate chloride ion diffusion coefficient and age apponent (m) The m values of the foundation with 4,000 class was 0.35 ~ 0.39, similar to KCI or ACI suggested values. essential service water constructions and tunnels of 5,000 class were 0.44 ~ 0.53 and 6,000 class, and 0.62 of reactor containment buildings were similar to the proposed values of FIB. As a result of the prediction of the service life with the measured age coefficient, all the safety related concrete structures of the nuclear power plants satisfied the service life of more than 60 years.

• Explosives and Blasting
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• v.21 no.3
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• pp.37-48
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• 2003

김해 국제공항 2단계 확장 공사 중 구 국제선 청사 발파해체공사"는 5.5초의 기폭시차를 두고 약 7초간에 구조물의 붕괴를 유도하여, 단기간에 안전하며 최대의 효율을 낼 수 있는 발파해체공법을 적용하여 시공하였다. 이에 따라 발파해체공사의 공법, 공정, 세부 현황 및 결과, 발파공해영향권에 대해 분석, 평가 하였다. 구 국제선청사 구조물은 3층 높이로 저층 구조물에 해당하고 구조물의 특성상 Span 간격이 길고 충고가 높다. 또한 지반이 액상한계점 상태까지 도달하여 구조안전진단 결과 위험등급인 D등급으로 판정되었다. 본 대상건물과 같이 충고는 낮지만, 구조 안전성 측면에서 위험 요소를 가지고 있으므로 발파공법을 적용하여 해체를 실시하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.191-194
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• 2000

최근의 삼풍백화점 붕괴사고 및 성수대교사고 등 대형사고의 원인을 살펴보면 건물의 안전진단 미비와 구조물의 안전관리 진단판정미비로 건축물의 붕괴를 예측하지 못한 결과이다. 이는 모든 불확실 시스템의 상태를 적당한 항목으로 판정 정규화한 계수값으로 나타내어 예방하지 못한 결과이다. 비단건축물 시스템뿐 아니라 실존 가시물(可視物)과 비가시물(悲歌視物)에 대해서도 비결정 상황의 상태표시계수를 예측하여 정규값으로 나타낼 필요가 있다. 즉, 교통도로의 교통량 특정, 통신신호의 수신율 측정 등을 최적화 예측할 수가 있게된다. 본 논문에서는 환경 및 시스템 출력값에 표시하여 어떤 결과를 가져오는지 확인하기 위하여 평면 상의 임의의 데이터의 조합으로부터 특정 데이타를 선택 최적화하는 과정을 실험화 하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.149-158
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• 2005

In order to grasp and evaluate the characteristics and the safety of traditional wooden building, we select one of the representative traditional wooden building, Buseoksa Muryangsujeon in this study. After the two and three-dimensional structural analysis of this building are performed, the results are compared and analyzed. Following main conclusion are obtained: 1) By comparison between the results of two and three-dimensional structural analysis, they show that the exterior members of this building tend to transfer more load in the three-dimensional analysis. 2) The result of three-dimensional structural analysis shows that the every member stress of Buseoksa Muryangsujeon except Chobang and Jangyon is below allowable stress. 3) For exact modelling of joints of members in traditional wooden building such as Gongpo, it is necessary to accumulate and analyze the technical data through structural test and systematic analysis study.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.55-64
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• 2017

In this paper, we propose and implement an IoT based mobile smart monitoring system in the view point of safety inspection for solar power generation. The main features and contributions of proposed system are as follows. First, the proposed system model can evaluate periodically in the view point of safety inspection the conditions of the system and structure of solar power generation. Second, the proposed system automatically re-processes the measurement data of the system and structure for solar power generation and save it into database. Third, using the re-processed and saved information, the proposed system can provide the monitoring information with webpage form to both administrator and owner of solar power generation system, thus they can measure and confirm directly in the view point of safety inspection the conditions of the solar generation structure without visiting those places. Fourth, the provided web pages for the monitoring of solar power generation can be accessed regardless of the system structures. The performance evaluations of the proposed system show that the proposed monitoring system can save efficiently the data received from the sensors installed in the structure of solar power generation into the data base in the collecting server. And the proposed system can support that both administrator and user of solar power generation system access webpage in real time without considering places by using mobile phone and desktop computer and obtain the information for the conditions of the system and structure of solar power generation with graph forms.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.95-103
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• 2016

The absolute value management method is widely used in the most of the earth retaining construction, which evaluates the safety by comparing measurement result and management criteria. Therefore, the management criteria is the standard to evaluate the safety of the site, and in other words, the criteria is a direct factor of the evaluation. That means that the safety of the site can not be acquired if the management criteria is not proper, even though the measurement system is perfectly set. However, many of field technicians do not have rely on the current management criteria, and they even recognize the necessity of the revision. Therefore, in this study, the necessity of the revision was studied. Also, the optimum criteria selection and the application were performed based on the test results of earth retaining deflection and probabilistic theory. The absolute value management method was used for this study. The details are tabulated.