• Title/Summary/Keyword: 외관조사망도

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Estimation of Image-based Damage Location and Generation of Exterior Damage Map for Port Structures (영상 기반 항만시설물 손상 위치 추정 및 외관조사망도 작성)

  • Banghyeon Kim;Sangyoon So;Soojin Cho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.5
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    • pp.49-56
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    • 2023
  • This study proposed a damage location estimation method for automated image-based port infrastructure inspection. Memory efficiency was improved by calculating the homography matrix using feature detection technology and outlier removal technology, without going through the 3D modeling process and storing only damage information. To develop an algorithm specialized for port infrastructure, the algorithm was optimized through ground-truth coordinate pairs created using images of port infrastructure. The location errors obtained by applying this to the sample and concrete wall were (X: 6.5cm, Y: 1.3cm) and (X: 12.7cm, Y: 6.4cm), respectively. In addition, by applying the algorithm to the concrete wall and displaying it in the form of an exterior damage map, the possibility of field application was demonstrated.

Establishment of a Standard Procedure for Safety Inspections of Bridges Using Drones (드론 활용 교량 안전점검을 위한 표준절차 정립)

  • Lee, Suk Bae;Lee, Kihong;Choi, Hyun Min;Lim, Chi Sung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.2
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    • pp.281-290
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    • 2022
  • In Korea, the number of national facilities for which a safety inspection is mandatory is increasing, and a safer safety inspection method is needed. This study aimed to increase the efficiency of the bridge safety inspection by enabling rapid exterior inspection while securing the safety of inspectors by using drones to perform the safety inspections of bridges, which had mainly relied on visual inspections. For the research, the Youngjong Grand Bridge in Incheon was selected as a test bed and was divided into four parts: the warren truss, suspension bridge main cable, main tower, and pier. It was possible to establish a five-step standard procedure for drone safety inspections. The step-by-step contents of the standard procedure obtained as a result of this research are: Step 1, facility information collection and analysis, Step 2, analysis of vulnerable parts and drone flight planning, Step 3, drone photography and data processing, Step 4, condition evaluation by external inspection, Step 5, building of external inspection diagram and database. Therefore, if the safety inspections of civil engineering facilities including bridges are performed according to this standard procedure, it is expected that these inspection can be carried out more systematically and efficiently.

A Method for Information Management of Defects in Bridge Superstructure Using BIM-COBie (BIM-COBie를 활용한 교량 상부구조의 손상정보 관리 방법)

  • Lee, Sangho;Lee, Jung-Bin;Tak, Ho-Kyun;Lee, Sang-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.2
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    • pp.165-173
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    • 2023
  • The data management and the evaluation of defects in the bridge are generally conducted based on inspection and diagnosis data, including the exterior damage map and defect quantity table prepared by periodic inspection. Since most of these data are written in 2D-based documents and are difficult to digitize in a standardized manner, it is challenging to utilize them beyond the defined functionality. This study proposed methods to efficiently build a BIM (Building Information Modeling)-based bridge damage model from raw data of inspection report and to manage and utilize the damage information linking to bridge model through the spread sheet data generated by COBie (Construction Operations Building Information Exchange). In addition, a method to conduct the condition assessment of defects in bridge was proposed based on an automatic evaluation process using digitized bridge member and damage information. The proposed methods were tested using superstructure of PSC-I girder concrete bridge, and the efficiency and effectiveness of the methods were verified.

Development of a Building Safety Grade Calculation DNN Model based on Exterior Inspection Status Evaluation Data (건축물 안전등급 산출을 위한 외관 조사 상태 평가 데이터 기반 DNN 모델 구축)

  • Lee, Jae-Min;Kim, Sangyong;Kim, Seungho
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.6
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    • pp.665-676
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    • 2021
  • As the number of deteriorated buildings increases, the importance of safety diagnosis and maintenance of buildings has been rising. Existing visual investigations and building safety diagnosis objectivity and reliability are poor due to their reliance on the subjective judgment of the examiner. Therefore, this study presented the limitations of the previously conducted appearance investigation and proposed 3D Point Cloud data to increase the accuracy of existing detailed inspection data. In addition, this study conducted a calculation of an objective building safety grade using a Deep-Neural Network(DNN) structure. The DNN structure is generated using the existing detailed inspection data and precise safety diagnosis data, and the safety grade is calculated after applying the state evaluation data obtained using a 3D Point Cloud model. This proposed process was applied to 10 deteriorated buildings through the case study, and achieved a time reduction of about 50% compared to a conventional manual safety diagnosis based on the same building area. Subsequently, in this study, the accuracy of the safety grade calculation process was verified by comparing the safety grade result value with the existing value, and a DNN with a high accuracy of about 90% was constructed. This is expected to improve economic feasibility in the future by increasing the reliability of calculated safety ratings of old buildings, saving money and time compared to existing technologies.

Disaster-Prevention System of Transportation Network used by GIS and Seismic Fragility Analysis (GIS 및 지진취약도 분석기법을 이용한 교통 네트워크의 방재 시스템)

  • Lee, Hyung-Jin;Park, Byung-Hee;Jang, Il-Young
    • Journal of the Korean Society of Hazard Mitigation
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    • v.6 no.2 s.21
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    • pp.25-35
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    • 2006
  • Recently seismic fragility analysis method has been widely used for the seismic probabilistic risk assessment of infrastructures such as nuclear power plants, buildings and bridges because of its probabilistic characteristics. Furthermore, this technique has been applied to large-scale social systems consisted of each infrastructures by combing GIS. In this paper, the applicability of this technique to domestic infrastructural systems was studied. The transportation network was selected as one of these domestic infrastructural systems. Example studies were peformed about Changwon city. Nonlinear time history analysis, with a maximal likelihood approach were conducted to establish the fragility curves of each infrastrucures (bridges). GIS analysis was also applied to the analysis of whole infrastructural systems. The results show that it is very useful to predict seismic probabilistic risk assessment of this domestic transportation network. However, it also shows that further studies such as more suitable damage criterion to domestic structure and precise nonlinear analysis techniques should be developed to predict more precise results.

Creation of Crack BIM in Bridge Deck and Development of BIM-FEM Interoperability Algorithm (교량 바닥판의 균열 BIM 생성 및 BIM-FEM 상호 연계 알고리즘 개발)

  • Yang, Dahyeon;Lee, Min-Jin;An, Hyojoon;Jung, Hyun-Jin;Lee, Jong-Han
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.6
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    • pp.689-693
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    • 2023
  • Domestic bridges with a service life of more than 30 years are expected to account for approximately 54% of all bridges within the next 10 years. As bridges rapidly deteriorate, it is necessary to establish an appropriate maintenance plan. Recent domestic and international research have focused on the integration of BIM to digitize bridge maintenance information and then enhance accessibility and usability of the information. Accordingly, this study developed a BIM-FEM interoperability algorithm for bridge decks to convert maintenance information into data and efficiently manage the history of maintenance. After creating an initial crack BIM based on an exterior damage map, bridge specification and damage information were linked to a numerical analysis that performs damage analysis considering damage scenarios and design loads. The spread of cracks obtained from the analysis results were updated into the BIM. Based on the damage spread information on the BIM, an automated technology was also developed to assess both the current and future condition ratings of the bridge deck. This approach can enable an efficient maintenance of the deck using the history data from bridge inspection and diagnosis as well as future information on cracks and defects. The expected early detection and prevention would ultimately improve the lifespan and safety of bridges.

Effect of Drying Methods on the Field Drying Rate and Quality of Alfalfa and Spring Oats Hay (건조방법별 알팔파와 봄 연맥의 건초조제 효과)

  • Seo, Sung;Kim, Jong-Geun;Chung, Eui-Soo;Lee, Jong-Kyong;Kim, Won-Ho;Shin, Dong-Eun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.21 no.2
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    • pp.67-74
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    • 2001
  • A field experiment was carried out to determine the effects of chemical/mechanical treatments at mowing on the field drying rate and hay quality of alfalfa(Medicago sativa L., cv. Vernal) and spring oats(Avena satvia L., cv. Swan). The chemical drying agent of 2% $K_2CO_3$, mechanical mower conditioning, and no treatment(control) were treated for hastening hay-making in the spring of 1997. The forages were harvested at early bloom stage in alfalfa and heading stage in oats. After field dry, square bales were made by hay baler, and the dry matter(DM) loss, visual estimation and nutritive value of hay were evaluated after storing two months. The field drying rates of alfalfa and oats were high at mechanical treatment, but the drying effectiveness of chemical agents alone was very low. With mower conditioning, the duration of field dry was shortened by 1 day compared with control. therefore, mower conditioning enhance the field drying rate of alfalfa and oats. The DM loss of alfalfa and oats hay was reduced by mechanical treatment, but the efficiency by chemical alone was low. The visual score(leafiness, green color, odor and softness) of hay at mechanical treatment was slightly higher than that of chemical and control. The nutritive value(ADF, NDF, in vitro digestibility, and relative feed value) of hay was also high with treatment of mechanical, but those of chemical alone were similar compared with control. The nutritive value of hay after two months in both alfalfa and oats was decreased when compared with at harvest.

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Effect of Mower Conditioner at Different Harvest Stage on the Field Drying Rate and Quality of Rye Hay (수확시기별 Mower Conditioner 처리에 의한 속성 양질 호밀 건초조제 효과)

  • Chung, E.S.;Seo, S.;Kim, J.G.;Kang, W.S.;Kim, J.D.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.19 no.3
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    • pp.251-258
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    • 1999
  • A field experiment was carried out to determine the effects of chemical /mechanical treatments at mowing on the field drying rate and hay quality of rye (Secale cereale L.). The chemical drying agent/mower conditioner ($K_2CO_3$ 2%, conditioning, $K_2CO_3$ 2% + conditioning and control) were treated at different harvest stage (late boot, heading and bloom stage) for hastening hay-making in the spring of 1996. After field dry, square bales were made by hay baler, and the dry matter(DM) loss, visual estimation and nutritive value of rye hay were evaluated after storing two months. The field drying rate of rye was higher with delayed stage of harvest, and mechanical and chemical + mechanical treatment, but the effectiveness of chemical alone was very low. With mower conditioning, the duration of field dry was shortened by 1.5 to 2 days compared with control. The DM loss of rye hay was reduced by late harvest and mechanical, and chemical + mechanical combined treatment, but the efficiency by chemical alone was very low. The visual score (Ieafiness, green color, odor and softness) of hay after storing was high in mechanical and chemical + mechanical, but the score by chemical alone was very low. The nutritive value (ADF, NDF, digestibility, and relative feed value) of hay was also high with treatment of mechanical and chemical + mechanical, but the quality by chemical alone was similar compared with control. The quality of hay was very low when harvested at bloom stage. In conclusion, mower conditioning can enhance the field drying rate of rye, but the drying effectiveness of chemical drying agent was very low. The effect of chemical/mechanical combined treatment was very similar when compared with mechanical alone. Harvest at early heading to heading stage was recommended for high quality rye hay.

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Cold Storage, Packing and Salting Treatments Affecting the Quality Characteristics of Winter Chinese Cabbages (월동 배추의 저온 저장 방법별 포장 및 염장 처리에 따른 품질 특성)

  • Lee, Jung-Soo;Choi, Ji-Won;Chung, Dae-Sung;Lim, Chai-Il;Park, Su-Hyung;Lee, Youn-Suk;Lim, Sang-Chul;Chun, Chang-Hoo
    • Food Science and Preservation
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    • v.14 no.1
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    • pp.24-29
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    • 2007
  • Quality changes in winter Chinese cabbages were evaluated during low temperature storage. Flesh and salt-treated Chinese cabbages were put into (a) polyethylene (PE) film sacks (size: $40cm{\times}60cm$, thickness: 0.03 mm, with four perforations each 8 mm in diameter), (b) plastic containers or (c) polypropylene (PP) nets and stored at $0^{\circ}C$. Also, Cabbages were also wrapped in newspapers and stored underground where the average temperature was $2.7^{\circ}C$. The weight loss rates of Chinese cabbages stored in PP nets and plastic containers were greater than those of cabbages stored with PE or wrapped in newspaper. Chinese cabbages wrapped in newspaper and stored underground needed much greater trimming compared to cabbages stored in other ways. The firmness and the soluble solid contents of Chinese cabbages were not affected by the various storage treatments. A better appearance was retained when Chinese cabbages were stored in PE film sacks. Chinese cabbages in PE film sacks stored at $0^{\circ}C$ showed delayed weight loss, less trimming loss, and less change in appearance. The quality changes in salted Chinese cabbages (desalting losses, pH changes, osmolarities, and crude fiber content) were not significantly different after the various treatments. No storage treatment was effective in maintaining a high quality of salted winter Chinese cabbage.