해상특수교량은 특수한 환경적 조건뿐 아니라 고주탑의 구조형식, 보호재로 쌓여있는 케이블 등 특 수한 형식을 가지고 있어 일반적인 육안전검으로 안전점검을 할 수 없는 사각지대가 존재한다. 주탑의 외부 손상상태 및 케이블의 손상에 대해서는 정밀안전점검에서도 점검이 되지 않는 경우가 대부분이 므로 이에 대한 대책 마련이 시급하다. 또한 해상특수교량에 대한 전문적인 경험과 기술이 부족한 관 리자도 대상교량의 손상과 이상거동을 직관적으로 확인하고 판단할 수 있는 지원체계가 필요하다. 이 에 본 연구에서는 해상특수교량 고주탑에 대한 손상정보를 파악하기 위하여 드론의 자동비행 기술을 개발하고 이를 이용하여 주탑 외부 균열 손상에 대한 안전점검을 실시하고 이를 분석하였다.
최근 지방정부는 지역경제 활성화를 위한 관광객 유치를 위해 다양한 모양 구조를 가지는 출렁다리 를 경쟁적으로 건설하고 있다. 이러한 출렁다리의 안전관리는 자체 가이드라인이나 국토교통부에서 발 간한 매뉴얼을 통해 관리되고 있으나 실제로는 관광이나 공원 관리 부서에서 관리하고 있어 안전관리 에 소홀한 실정이다. 국토교통부에서는 제3종시설물에 대한 안전점검 매뉴얼 발간하고 안전등급 평가 기준을 강화하여 기존 3분위(양호, 보통, 불량) 평가기준을 5분위(우수, 양호, 보통, 미흡, 불량) 평가체 계로 개정하였으며, 기존 세부지침과 평가기준도 일원화 하였다. 그러나 출렁다리의 경우 제1종, 제2 종 시설물인 교량과 달리 점검 방식 및 체크리스트가 달라져야 하므로 출렁다리 정기안전점검을 위한 점검 수준에 맞게 개선되어야 한다. 본 연구에서는 출렁다리에 안전전검에 체계 개선을 위한 출렁다리 정기안전점검 매뉴얼(안)을 제시하였다.
본 논문은 CFRP 그리드의 정착길이에 따른 콘크리트 보의 휨거동을 평가한 실험적 연구를 보고한다. 실험을 위해 폭 250 mm, 높이 125 mm, 길이 2000 mm의 실험체가 제작되었다. 실험변수로 CFRP 그리드의 정착길이(1000 mm, 800 mm, 700 mm, 600 mm, 500 mm, 400 mm, 300 mm, 200 mm)가 고려되었다. 실험체 제작 후 3점 휨실험이 수행되었다. 실험결과 모든 실 험체의 강성은 정착길이에 영향을 받지 않고 유사한 것으로 나타났다. 초기 균열하중은 모든 실험체에서 유사하게 나타났으나, 정착길이가 감소됨에 따라 최대하중, 최대하중 시의 처짐 및 변형률은 감소하는 경향을 나타냈다. 특히 부재 길이에 80% 이상 이 정착된 경우 부재 길이와 동일한 정착길이를 가진 콘크리트 보의 약 90% 이상의 구조성능을 확보할 수 있는 것으로 확인되 었다. 제안된 수치해석 모델은 CFRP 그리드의 정착길이가 감소됨에 따른 극한하중의 저하를 유사하게 예측하였으며, 극한하중 의 오차는 평균 13.1%로 CFRP 그리드의 정착길이에 따른 콘크리트 보의 휨성능을 비교적 정확하게 예측하는 것으로 나타났다.
This study reports an analytical investigation on the development of SB4-grade separated concrete median barriers. The proposed barrier sections comprise three designs, with heights of 810, 1000, and 1270 mm and upper widths of 90, 120, and 120 mm, respectively. Before conducting collision analyses on the proposed sections, the considered collision analysis model was validated using real collision test results; the model was found to accurately predict the real collision test results. The proposed cross-sections were modeled to perform collision analysis according to SB4-grade collision conditions. Results indicated that increasing the cross-section height increased the damaged area and decreased the strength, while the occupant protection performance remained mostly unaffected. Furthermore, the proposed cross-sections met the strength and occupant protection performance criteria specified in domestic guidelines, suggesting their suitability as a separated concrete median barrier for bridges.
This study is an experimental study to evaluate the vehicle-protection performance of the reinforced F section of a concrete median barrier. To reinforce the strength performance and durability of the F section, the design strength of concrete was increased and a wire mesh was added. The reinforced F section was tested in an actual collision to verify the protection performance of the SB4 class(Impact Severity: 160kJ) concrete barrier. In the truck-crash test for strengthperformance evaluation, no damage or no sufficient scattering occurred to cause damage to a third party. In addition, the truck smoothly moved through an escape box after the collision. THIV and PHD, which are criteria for evaluating the occupant-protection performance, were measured at 75% and 64% of the limit, respectively, and were confirmed to provide good occupant-protection performance. The vehicle rotations after the collision were 12%–19% of the allowed limits.
기계식 신축이음장치는 온도변화, 크리프 등에 의한 상부구조 수평변위를 수용하고 불연속면을 연속화시켜 차량의 주행을 원활하게 하는 교량부속장치이다. 하지만 윤하중의 직접재하 및 제설제 등에 노출되어 신축이음장치의 파손, 후타콘크리트 균열 및 탈락 등 많은 문제를 동반하고 있다. 이러한 신축이음장치는 교량 공용기간 중 약 10년 주기로 교체 공사가 필요한 소모성 구조부재이며 매년 동일한 수준의 국가 예산이 지출되고 있는 실정이다. 이에 본 연구에서는 기존의 신축이음 교체 공사 시 기존 교량에 무조인트 교량 시스템을 도입하여 유지관리 비용을 저감할 수 있도록 하였다.
The purpose of underwater survey is to provide basic data for proper maintenance and reinforcement to detect waterborne defects as early as possible, to prolong the life of bridges and to ensure safety. This study suggests an underwater investigation item and method to be observed by the inspector in checking the substructure of the marine bridge. However, due to the limit that can not deal with the characteristics of the area where maritime bridges are installed in detail, it is considered desirable to use this point as a minimum safety and performance standard in underwater survey sites and management bodies.
The purpose of this study is to prevent the occurrence of safety accidents and traffic accidents in winter by presenting the criteria of de-icing and anti-icing of cable-supported marine bridges. In winter, due to the structural characteristics of the cable support bridge, the main tower and the cable are positioned upon the reinforcing beam that the vehicle passes through, and snow and ice that piled on the main tower and the cables is fall to the road. so It can be a reason of the traffic accident. In this study, we analyzed the mechanism for the snow accretion and ice accretion and suggested preventive measures about de-icing and anti-icing.
This guideline refers to expansion joints with a diameter of 300mm or more. It will check the condition of large-capacity expansion joint, detect abnormal behavior and damage early, take appropriate measures such as repair and replacement, and secure user's safety and smooth traffic flow. And to provide the basic data necessary for the maintenance work of the management subject to be carried out for the purpose of To this end, we investigated and analyzed the existing joint damage, repair and replacement cases, suggested proper repair and replacement methods and preventive maintenance plan.
Ministry of Oceans and Fisheries has developed the port facility management system(POMS) that can be run systematically manage safety inspection and maintenance results about the mooring facilities, counter facilities and pier pavement in a national 60 port. This paper contains a description of the POMS.
Ministry of Land, Infrastructure and Transport(MOLIT) publishes Yearbook of Road Bridge and Tunnel Statistics once every year. Also, Korea Institute of Civil Engineering and Building Technology(KICT) is operating the website based on GIS to provide the status information of bridges and tunnels on the road. In this paper introduces road Bridge and Tunnel Information(BTI) system that offers the base data for the effective maintenance of bridges and tunnels on the road.
The collapse of a large infrastructure cause serious losses. Therefore, there has been an increasing demand in using Structural Health Monitoring techniques for the building structures so that their maintenance cost and time can be reduced. In this study, a experimental evaluation of abnormal behavior using data from a seismograph that already installed for potential of low-cost safety assessment.
A portable device which calculate and analysis the SOC structure data. This device can be used to estimate the building prior to install the sensing system. This sensing tools can help the system engineers to analyze the large SOC structure’s responses.
Based on the study of current status for domestic port facility management system, it was used to collect information for building the ocean & port facility integrated management system.
A object of this Experiment is to present a experimental method to verify the detection algorithm of abnormal behavior In order to achieve the desired, a cable stayed bridge model was prepared. The experiments lead to damage of stiffening girders and measuring this by changing the weight.
The collapse of a large infrastructure cause serious losses. Therefore, there has been an increasing demand in using Structural Health Monitoring techniques for the building structures so that their maintenance cost and time can be reduced. In this study, a structural health monitoring methodology using dynamic responses is proposed for damage area estimation of a prototype building structure during shaking table testing in different positions of structural damage.
All living organisms use memory and oblivion algorithms considering the estimated lifetime and the changes in the ambient environment. Because of the expected lifetime of a bridge is similar to the human’s one, if a bridge uses the same algorithm of human memory, the abnormal responses of the structure can be easily detected. This paper introduces unfamiliarity index (UFI) that calculated from the FFT results of the short term timeline acceleration responses. If this algorithm, which can detect an abnormal behavior from the maximum constant signal, is used to the terminal sensors of an structure, more accurate safety control criteria will be prepared efficiently.