• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.532-541
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• 2016

The objective of this paper is to support accurate pavement condition assessment and decision of proper maintenance method and time by conducting visual inspection and calculating the remaining life of pavement from falling weight deflectometer(FWD) data. Each was implemented in the same long-term performance pavement(LTPP) sections. Visual inspection was executed to measure pavement condition indices such as crack, rutting and international roughness index(IRI) and the Seoul Pavement Index(SPI) was calculated based on these results. The dynamic modulus was back-calculated from the FWD data. The remaining pavement lives were determined from equivalent single axle loading(ESAL) and FWD data. Correlation of maintenance priority by each result value was examined. Consequently, the correlation between remaining life to Crack and Rutting was higher than the other factors or indicesbecause IRI is not related to FWD value and SPI value consists with IRI value and other indices. The R-square value of correlation of FWD with Crack and Rutting was 0.65, which indicated an insufficient correlation. Consequently, when decision of maintenance of method, time, etc. is determined, FWD data have to be considered with Crack and Rutting because of those relations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.27-35
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• 2019

The purpose of this study is to analyze the displacement characteristics in slow-moving landslide area using digital elevation model and airborne LiDAR when unpredictable disaster such as slow-moving landslide occurred. We also aimed to provide basic data for establishing a rapid, reasonable and effective restoration plan. In this study, slow-moving landslide occurrence cracks were selected through the airborne LiDAR data, and the topographic changes and the scale of occurrence were quantitatively analyzed. As a result of the analysis, the study area showed horseshoe shape similar to the general form of slow-moving landslide occurrence in Korea, and the direction of movement was in the north direction. The total area of slow-moving landslide damage was estimated to about 2.5ha, length of landsldie scrap 327.3m, average width 19.3m, and average depth 8.6m. The slow-moving landslides did not occur on a large scale but occurred on the adjacent slope where roads were located, caused damage to retaining walls and roads. The field survey of slow-moving landslides was limited by accessibility and safety issues, but there was an advantage that accurate analysis was possible through the airborne LiDAR. However, because airborne LiDAR has costly disadvantages, it has proposed a technique to mount LiDAR on UAV for rapidity, long-term monitoring. In a slow-moving landslide damage area, information such as direction of movement of cracks and change of scale should be acquired continuously to be used in restoration planning and prevention of damage.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.9-17
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• 2018

PURPOSES : The frequency and severity of natural disasters such as torrential rain or typhoons have become increasingly significant worldwide. Events such as summer typhoons and localized torrential downpour can cause severe damages to a residential area and road networks, resulting in serious harm to the daily lives of people, especially in rural areas by isolating residents from road networks. An immediate and emergency repair technology for the collapsed road networks is urgently needed. This study introduces a new technology to repair road bases or slopes. METHODS : The development of new technology for emergency and permanent repair consists of first, packing of cement paste-coated gravel, second, combining appropriate equipment, and third, conducting a field applicability test. In this research, the compressive strength of cement pastecoated gravel, gravel-netting concrete properties, and packing efficiency were determined, and a full scale field mock-up test was carried out. RESULTS : The compressive strength of the cement paste-coated gravel concrete satisfied the required limit for road base of 5 MPa after 7 days. With appropriate netting materials and packing size, gravel-netting concrete was successful up to a slope of 1:1.5. The full scale field mock-up test showed efficiency in the field and penetration resistance performance. CONCLUSIONS : The new technology of emergency and permanent repair for damaged road bases and slopes, introduced in this study, showed satisfactory performance. The technology is expected to be applied in the field when construction procedures and quality specifications are made.

• Journal of Korean Society of Steel Construction
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• v.15 no.4 s.65
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• pp.341-358
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• 2003

This paper proposed a general formulation of Life-Cycle Cost (LCC) models and LCC effective design system models of steel bridges suitable for practical implementation. An LCC model for the optimum design of steel bridges included initial cost and direct/indirect rehabilitation costs of a steel bridge as well as repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socioeconomic losses. The new road user cost model and regional socioeconomic losses model were especially considered because of the traffic network. Illustrative design examples of an actual steel box girder and an orthotropic steel deck bridge were discussed to demonstrate the LCC effectiveness of the design of steel bridges. Based on the results of the numerical investigation, the LCC-effective optimum design of steel bridges based on the proposed LCC model was found to lead to a more rational, economical, and safer design compared with the initial cost-optimum design and the conventional code-based design.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.59-67
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• 2012

This study presents the evaluation of the patching materials that are used to repair the distress of asphalt pavement. Four kinds of patching materials currently used in practice were tested in both laboratory and field. The laboratory tests included the dry and soaked Marshall stability test, indirect tensile test, wheel tracking test and adhesive strength between the asphalt pavement and the repairing material was tested as a performance test. The field study was conducted using the slab samples placed on the location of vehicle tire passing and the performance of the repairing materials were investigated as passing the traffic load. The result of the laboratory tests were satisfied with the current design criteria and material standard except for water-immersion stability. Type C patching material showed the highest adhesive shear strength among the patching materials tested. However, the mature distress, such as rutting and stripping were monitored after construction in 10 days. It was found that performance of patching material is lack of quality behavior when they were applied in the field and required to develop and applu to prevent the mature distress of the current patching materials.

• Journal of Korean Society of Disaster and Security
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• v.13 no.4
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• pp.37-46
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• 2020

Although the importance of resilience is emerging around the world, the single definition of resilience related to natural disasters is not clear. The reason for this is that there is no specific definition of how the definition of resilience relates to similar terms such as vulnerability, recovery, adaptability, and sustainability. In addition, it is because each country and region have different geographic and geological characteristics, and each measurement index is different, just as typhoons, droughts, and earthquakes have different types of disasters. Therefore, in this study, the definition of resilience is reflected in the spatial characteristics of this study as the ability to recover from'complex disasters (concentrated heavy rain, landslides, earth and stone flows) occurring on local roads or on local roads adjacent to people or facilities. Defined. And it was divided into DRR: Disaster Resilience focusing on the Road. In addition, domestic and foreign literature surveys were conducted to derive road-centered disaster resilience factors, and a hierarchical structure was established and AHP survey was conducted to establish a DRR evaluation system. As a result of the analysis of the AHP survey, the weight of direct road disaster influencing factors (drainage facilities, protection facilities, etc.) located inside local roads was 0.742, and the weight of indirect road disaster influencing factors (population, property, etc.) located near local roads. Was found to be 0.258, indicating that the direct impact factor of road disaster was relatively higher than that of the indirect impact factor.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2001.03a
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• pp.204-218
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• 2001

절토사면은 토층, 풍화토, 풍화암, 연암, 경암 등의 풍화도가 다른 물질로 구성되어 있어 지반구성 물질에 대한 공학적인 판단이 쉽지 않으며 시공 중 또는 후에 사면의 안정성 문제가 대두되고 있는 실정이다. 사면의 안정성 문제는 과거 30여 년 동안 고속도로의 많은 절토사면에서 경험되어 왔으며 현재에도 계속적으로 사면붕괴 및 복구를 경험하고 있으나 체계적인 관리 및 조사가 이루어지지 않고 있다. 따라서, 본 연구는 절토사면의 체계적인 관리체계의 구축과 효율적인 자료분석을 위하여 사면관리용 데이터베이스 프로그램을 개발하였다. 이들 관리프로그램을 활용한다면 국내에 분포하는 암반의 내적 요인들에 대한 지질 공학적인 특성을 파악할 수 있으며 지역에 따라 분포하는 암석종류, 지질시대 및 지질구조에 따라 붕괴유형 및 발생빈도 등을 분석함으로써 도로 및 주택단지의 개설시 예비적인 사면안정문제를 예견할 수 있을 것으로 판단된다.

• 월간 기계설비
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• s.295
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• pp.57-68
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• 2015

내전 후 전쟁 상처를 복구 중에 있는 이라크는 주택, 인프라, 사회 서비스망 구축의 필요에 따라 지난 2010년 이라크 기획청(Ministry of Planning, MOP)이 이라크의 삶의 질 개선을 위한 국가개발계획(Iraq National Development Plan, 2010 ~ 2014)을 수립하고 15개 주정부와 쿠르드 자치정부 지역에 100만호 주거 시설 제공을 위한 국가 주택 프로그램을 발표했다. 이에 따라 2017년까지 주택과 교통인프라, 에너지, IT, 의료, 보안 등에 걸쳐 총 2,750억불(약 300조원)을 이라크 재건사업에 투자할 계획이다. 또 2030년까지는 에너지 분야에 5,000억불 투자 등 정유공장, 발전소, 도로, 인프라, 공공시설 및 군시설 등 다양한 분야에 최소 7,000억불에 달하는 예산을 투입할 예정이다. 한화건설은 지난 2012년 80억 달러 규모의 이라크 비스마야 신도시 건설공사를 수주해 우리나라 해외건설 역사상 최대 규모의 프로젝트 기록을 세웠다. 또한 이 계약으로 우리나라 해외건설 누적 수주액 5,000억 달러 돌파에 크게 기여했다. 윤창기공(주)(대표 백종윤)는 비스마야 현장에서 PC 플랜트 현장의 기계설치공사와 하우징 현장의 기계설비 및 소방공사를 담당하고 있다. 본지는 이라크 현장에 있는 윤창기공(주) 정몽준 소장과 김용우 소장을 이메일로 만나 보았다.

• 전기의세계
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• v.45 no.4
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• pp.20-24
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• 1996

오늘날 전력사용이 급증하면서 부하가 대용량화되는 추세에 따라 전기설비의 규모는 점차 대규모화 되고, 사회는 점점 고도정보화 사회로 발전되고 있다. 따라서, 설비의 사고 및 정전 등은 높은 전기적 의존도를 가진 고도 산업사회에 막대한 경제적 손실 및 장애를 가져다준다. 한편, 도시 환경의 미화차원에서 지중배전선로는 점차 증가하고 특히, 전력 케이블은 주로 공장 또는 대도시의 도로지반하에 분포하고 있어 사고시 복구에 많은 시간이 필요하며 교통 및 산업활동에 막대한 피해를 끼치게 된다. 이러한 반면에 우리나라에서는 배전용 케이블로 CV 케이블을 포설하기 시작한지 20여년이 경과되어 최근에 사고가 점증하고 있는 추세이다. 그리고, 근래에 포설한 케이블이라 할지라도 시공불량 및 기타 열악한 환경에 놓여 있게 되면 단시간에도 사고에 이를 수가 있어 설비 및 수용가에 원활한 전력공급 및 사고의 미연 방지를 위해 케이블의 열화상태를 정기적으로 진단할 필요가 있으며, 이를 위한 예방진단 기술의 연구가 필요로 하게 되었다. 본 논문은 이러한 배경하에서 케이블에서의 열화사고 현황, 절연 열화요인과 열화 process 그리고 절연진단기술의 현황 등을 알아보고, 국내 배전선로 계통인 3.3kV 및 6.6kV급 CV 케이블의 열화 진단기술 현황 및 향후 전망에 대하여 기술하였다.

• Journal of the Korean Society for Railway
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• v.6 no.1
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• pp.14-18
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• 2003

최근 우리나라는 지구온난화에 따른 엘니뇨, 라니뇨등 세계적인 이상기후에 의한 국지성 호우가 매년 다발하고 있으며, 이에 따른 철도선로피해도 기상상황 악화와 동반하여 증가 추세에 있다. 또한 국내에서 자주 발생하는 대표적인 재해 원인으로는 태풍을 들 수 있는데 이와 같은 태풍은 매년 7월에서 8월 사이에 우리나라를 관통하면서 막대한 피해를 유발시킨다. 특히 2002년 8월 31일부터 9월 1일까지 한반도를 관통한 제15호 태풍 루사(RUSA)는 약 이틀동안 최대시간강우량 101mm/hr, 총 강우량 898mm의 사상유례 없는 강우와 강풍을 동반하며, 도로ㆍ철도ㆍ농경지ㆍ가옥 등 국내 전 기반시설에 대하여 막대한 피해를 입혔다. 특히 철도의 경우 총48개소의 피해지역이 발생하였으며, 이로 인한 복구비용만도 약 1,472억원 정도로 추정하고 있다. (중략)