• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.1
• /
• pp.117-124
• /
• 2010

Different to other social infrastructures, bridge elements or bridges can be damaged or collapsed and this may cause death toll and severe social and economical damage, bridges should be managed to maintain a safety level. Diverse strengthening methods is developed to improve a deteriorated bridge performance up to original design level. But rational decision-making process and methodologies to select a optimum strengthening method are absence yet in Korea. This paper therefore derived items and proposed methodologies for quantity estimate considering uncertainty to select a optimum strengthening method among conceptually designed alternatives. And also, to demonstrate the applicability and verification of the proposed approach, it was applied to select the optimum strengthening method for the deteriorated T-shape concrete girder bridge. The model and the procedure can greatly contribute to the uncertainty-oriented alternative selection.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.193-193
• /
• 2019

기후변화로 인한 거대 자연재해 발생의 위험이 지속적으로 증가하고 있으며, 국외의 경우 주요정부기관, 보험사 및 연구기관 중심으로 자연재해 피해예측 모델을 개발하여 사용하고 있다. 침수사고 인한 피해는 건물은 물론이고 가재도구, 재고자산, 기계시설 등의 내용물에서도 발생하며, 건축물 신축단가 등을 이용해 비교적 쉽게 자산가치를 산정할 수 있는 건물구조물과 다르게, 건물내용물의 자산가치는 시설물의 업종, 용도, 사용자 특성 등에 따라 변동성이 큰 특징이 있다. 내용물의 피해액 추정을 위해 자연재해 피해예측 모델은 건물 구조물과 내용물 가치의 비율인 CSVR(Contents to Structure Value Ratio)을 사용하며, CSVR은 시설물 용도에 따른 자산가치평가 통계를 이용해 산정할 수 있다. 충분한 자산가치평가 DB를 확보할 경우 CSVR의 정확도 확보가 가능할 것이며, 이를 위해 국내에서는 민간보험사의 재물보험 계약 4만여건의 건물, 내용물 보험가입금액을 행정안전부 도로명전자지도에서 분류하는 건물 용도에 따라 분석한 연구결과가 있다. 하지만, 일반적으로 보험가입단계에서 대략적으로 추정하는 보험가입금액과 실제 자산의 가치는 차이가 있을 수 있지만, 보험가입물건의 실제 자산가치는 일부만 DB화 되어 있는 단점이 있다. 본 연구에서는 사고 발생 후 작성되는 손해사정보고서에서 평가한 정확한 자산가치 DB를 수집하여, 보험가입금액을 기준으로 산정한 CSVR의 결과와 비교하였다. 손해사정보고서에서 평가한 실제 자산가치를 기준으로 분석한 CSVR과 보험가입금액을 기준으로 산정한 CSVR은, 업종에 따라 유사하거나 큰 차이를 보이는 경우도 있었으며, 침수로 인한 정확한 피해액 추정을 위해서는 보다 양질의 DB확보를 통한 CSVR의 정확도 확보가 필요한 것으로 분석되었다.

• Journal of the Korean GEO-environmental Society
• /
• v.22 no.11
• /
• pp.23-29
• /
• 2021

Recently, ground subsidence has been steadily occurring mainly in downtown areas, threatening the safety of citizens. Under the road, various underground facilities such as water supply pipe, sewage pipe, and communication pipe are buried. Due to the aging of these underground facilities and the reckless development of the underground, it is acting as a cause of ground subsidence. Although there is a result of analyzing the risk of ground subsidence according to the deterioration of the existing pipeline, there is no result of analyzing the risk of ground subsidence using the density of pipelines indicating ground disturbance. Therefore, in this study, the density of the underground space was analyzed using the data of six types of representative underground pipelines in Seoul, and a study was conducted on whether there is a correlation with the ground subsidence. As a result, it was found that the density of underground facilities is high in the area where the ground subsidence occurred, indicating that the density of pipelines have an effect on the ground subsidence.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.288-288
• /
• 2023

도로, 철도 등의 횡단통로, 오폐수관로, 지하배수관 등 연약지반에서 상재하중과 부등침하에 의한 파괴 위험을 줄이기 위해 구조적인 안전성과 내구성이 개선된 다양한 관로들이 활용되고 있다. 관은 매설특성에 따라 콘크리트관, 도관, 합성수지관, 덕타일 주철관, 파형강관, 유리섬유 강화 플라스틱과 폴리에스테르수지 콘크리트관 등의 종류로 구분된다(환경부, 2017). 수리설계 시 이러한 관의 단면 규모 결정 및 흐름 특성을 파악하기 위해 관수로 유량측정에 이용되는 Manning의 경험식을 이용하고 있으며, 관로의 주요 재질에 따른 다양한 조도계수가 제시되어 있다. 새로운 재질을 이용하여 제작된 관은 수리실험을 통해 조도계수를 결정하는 것이 바람직하지만, 조도계수 실험은 대규모의 실험시설과 유량공급이 요구되기 때문에 여러 한계가 있다. PE관의 경우, 미국의 ASTM 표준에 의해 저밀도 폴리에틸렌(LDPE), 선형 저밀도 폴리에틸렌(LLDPE), 고밀도 폴리에틸렌(HDPE) 등으로 분류되는데 본 연구에서는 HDPE 재질의 서로 직경이 다른 다중벽관 PE관을 대상으로 조도계수를 결정하기 위한 현장 실규모 수리실험을 수행하였다. 본 실험에서는 식생, 수로의 불규칙성, 수로노선, 침전과 세굴, 장애물, 계절적 변화, 부유물질과 소류사는 무시되며 표면조도, 관의 크기와 형상, 수위와 유량이 조도계수에 영향을 미치는 주요 인자라고 할 수 있다. 수리실험은 실물모형(Prototype)으로 한국농어촌공사 농어촌연구원의 대형수리모형실험장에서 수행되었으며. 길이 24 m, 직경 150 mm의 PE 관은 고정식 개수로, 직경 800 mm의 관은 대형유사순환수로에 각각 설치되었다. 관로의 전면에 차폐막을 설치하여 상류부 수위를 안정시킨 상태에서 실험을 수행하였고, 차폐막으로부터 하류방향으로 약 7 m(측정기준지점), 11 m, 13 m, 15 m, 17 m 떨어진 곳에서 각각 수위와 유속을 측정하였다. 실험 결과, φ150관은 직경대비 수심이 클수록 조도계수가 감소하는 경향이 나타났고, φ800관은 직경대비 수심의 변화에 따른 조도계수의 경향이 크게 드러나지 않았다. 결론적으로 PE관의 조도계수는 수심별로 변화하는 것으로 나타났으며, 특정 수심을 지나면 조도계수가 다시 감소할 것으로 판단된다.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.2
• /
• pp.182-194
• /
• 2023

Traffic impact assessment plays a crucial role in resolving traffic issues that may arise during the implementation of urban and transportation projects. However, reported results diverge, presumably because the items reviewed differ. In this study, we analyze traffic improvement measures approved for traffic impact assessment, identify key items, and present items that should be included in assessments. Specifically, TF-IDF and N-gram analysis and text mining were performed with focus on urban development projects approved in Gyeonggi Province. The results obtained show that keywords associated with newly established transportation infrastructure, such as roads and intersections, were essential assessment items, followed by the locations of entrances and exits and pedestrian connectivity. We recommend that considerations of the items presented in this study be incorporated into future traffic impact assessment guidelines and standards to improve the consistency and objectivity of the assessment process.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.1A
• /
• pp.1-13
• /
• 2008

The web of a horizontally curved plate girder bridge is, in general, subject to not only longitudinal flexural in-plane stress but also out-of-plane bending stress. Therefore, the induced stresses in the fillet welded joints at the intersection of the web and flange plates in the curved plate girder bridge can be considerably high, and the welded joints of gusset plates connecting the main girder to the floor beams or sway bracings can be subject to much more severe situation than those in the ordinary straight plate girder bridge. In order to investigate the cause of fatigue crack occurred in a curved girder bridge that has been served in about 23 years, in this study, field load tests have been performed to obtain the stress characteristics at the welded joint under the real traffic flow. Using the test results, we have investigated the causes of the occurrence of various fatigue cracks and have estimated the fatigue lives for the cracks. In addition, the characteristics of structural behavior at welded joint of the curved girder bridge have been examined by comparing the FE analysis and the field test result.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.37 no.2
• /
• pp.26-35
• /
• 2009

This study is an analysis of the design changes of children's play facilities and the related rules and regulations which causes these changes. Accordingly, it is noticed that a site's change of design by legislation and by yearly alternation influences playground design. First, after revising the provisions for the distance from roads and parking lots, the constructing of safety fences between play facilities and the using of durable materials, alterations of the designs have been made a reality. Second, the design changes after the period of regulation transitions were caused by provisions related to the shelter of evergreens and conditions of the sun. Third, the changes of the playgrounds were related to the substitution of exercise facilities for the local residents and in carrying out a hygiene exam more than twice a year. Because a lack of regulatory standards for the design of playgrounds resulted in compliance based on individual interpretation and because a substitution of exercise facilities is part of the way to alleviate these regulations, the conditions of the site under investigation could be projeced. By such changes of regulations and analysis of alterations of playground design, programs for improvement were suggested. It turned out that the composition of the concrete standard in conformity with regulations required closer observance. Moreover, design standards for children's playgrounds are needed, such as the provision of variation in external appearance, the creation of more flexible layouts and the outlining of spaces by themes.

• International Journal of Highway Engineering
• /
• v.13 no.3
• /
• pp.157-165
• /
• 2011

With respect to the trend of highway traffic accident, highway accident is in decline, whileas, the fatality is on an increasing trend. Thus, many efforts to decrease highway traffic accidents and improve the safety, are required. In particular, in case of highway, the management standard by grade for accident black spot is designated. Thus, investing the effect factors by grade for highway traffic accident is required in detail. Thus, in this study, the factors affecting the traffic accidents among the environmental factors based on the graded data for the accident black spot in the applicable section targeting the Seoul-Pusan Express Highway, were reviewed; accident forecasting model which would analyze the characteristics of the accidents for determining the accident grade, was developed. As a result of establishing a model by using Quantification Theory of Type II, considering the characteristics of the dependent and independent variables based on the geometric structure, 'the fixed variable' among the variables relating to the accident, for the variables influencing over the accident grade, 'the type of vans, a chassis and people', 'the trailers, special vehicles and chassis people' and 'the negligence of watching and cloudy weather' were analyzed as common factors, in case of 'horizontal alignment', 'longitudinal slope' and, 'barricade' respectively.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.1
• /
• pp.185-194
• /
• 2014

This study investigates the methodology to evaluate the quantified performance of pavement markings and traffic guide signs using digital images. This methodology is significant to attempt to quantify their performance without large brightness photometer at the nighttime and bad weather. The retroreflective performance of pavement markings are evaluated through the contrast of gray levels of pavements and markings in collected digital images under the case of rain, dampness, and dryness. In addition, the appraisal of retroreflective performance of traffic guide signs are implemented through the comparison between interior illuminated and the existing retroreflective traffic guide signs using the contrast of luminance extracted from the value of RGB of backgrounds and legends in collected digital images according to geometric design, driving lanes, and the distance between the car and the sign. As a result, the retroreflective performance of pavement markings deteriorates about 3.5 times and 2 times under the case of rain and dampness respectively than dryness. Also, the performance of the existing traffic guide signs is significantly influenced by geometric design, driving lanes, and the distance, otherwise interior illuminated traffic guide signs. This methodology can be utilized to construct objective information of performance of traffic safety facilities to select appropriate position of expensive high reflective pavement markings and interior illuminated traffic guide signs considering diverse weather and geometric design.

• International Journal of Highway Engineering
• /
• v.5 no.3 s.17
• /
• pp.31-42
• /
• 2003

The KHC Test Road project was initiated on 1991 to develop Korean Pavement Design Guide. It was constructed along the Joongbu Inland Expressway line between Yeoju and Gamgok. It is two-lane wide expressway containing fifteen asphalt and twenty-five Portland cement concrete test pavement sections. Various sensors were installed in the Test Road to evaluate the behavior of test pavement sections under the influence of traffic load and environmental change. The most important issues in the sensor installation are the accurate location and long-term survivability. They are directly influenced by the sensor installation methodology. The methodology for asphalt strain gages is mainly discussed in this paper because it is the second important sensors in the KHC Test Road project. In order to find the best methodology, we evaluated existing methodology from prior experience and several conducted test installations. We have tried mound, block out, and trench cuts since 2000. Among three methods, block out was the most effective one in terms of accurate location, long-term survivability, and material homogeneity. However, this method cannot be applied to the wearing coarse so that the mound method was used as an alternative. The block out method was applied to base and intermediate layers while the mound method was used to the wearing coarse. Three hundred seventy-four asphalt strain gauges were installed on asphalt pavement sections from September 3rd to November 18th in 2002. According to the sensor measurement evaluation, 6.3% of sensor demonstrated over ranged readings for mound method installation and 2.5% did for block out method installation. We lost only two sensors during the installation. It is 99.5% survival and it is excellent survival rate according to other experience.