• 제목/요약/키워드: road bridge

검색결과 435건 처리시간 0.021초

Structural evaluation of Aspendos (Belkis) Masonry Bridge

  • Turker, Temel
    • Structural Engineering and Mechanics
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    • 제50권4호
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    • pp.419-439
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    • 2014
  • In this study, the structural performance of a seven span masonry arch bridge was evaluated. Investigations were performed on Aspendos (Belkis) Masonry Arch Bridge which was located on road of Aspendos Acropolis City in Antalya, Turkey. The old bridge was constructed in the early of fourth century AD, but it was exposed to the earthquakes in this region and the overloading by the river water. The old bridge was severely damaged and collapsed by probably an earthquake many years ago and a new bridge was then reconstructed on the remains of this old bridge by Seljuk in the 13th century. The bridge has also been affected from overflowing especially in the spring of each year, so some protective measures should be taken for this monumental bridge. Therefore, the structural performance under these loading has to be known. For this purpose, an initial finite element model was developed for the bridge and it was calibrated according to ambient vibration test results. After that, it was analyzed for different load cases such as dead, live, earthquake and overflow. Three load combinations were taken into account by deriving from these load cases. The displacements and the stresses for these combination cases were attained and compared with each other. The structural performance of Aspendos Masonry Arch Bridge was determined by considering the demand-capacity ratio for the tensile stress of the mortar used in Aspendos Masonry Arch Bridge. After these investigations, some concluding remarks and offers were presented at the end of this study.

Hilbert transform based approach to improve extraction of "drive-by" bridge frequency

  • Tan, Chengjun;Uddin, Nasim
    • Smart Structures and Systems
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    • 제25권3호
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    • pp.265-277
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    • 2020
  • Recently, the concept of "drive-by" bridge monitoring system using indirect measurements from a passing vehicle to extract key parameters of a bridge has been rapidly developed. As one of the most key parameters of a bridge, the natural frequency has been successfully extracted theoretically and in practice using indirect measurements. The frequency of bridge is generally calculated applying Fast Fourier Transform (FFT) directly. However, it has been demonstrated that with the increase in vehicle velocity, the estimated frequency resolution of FFT will be very low causing a great extracted error. Moreover, because of the low frequency resolution, it is hard to detect the frequency drop caused by any damages or degradation of the bridge structural integrity. This paper will introduce a new technique of bridge frequency extraction based on Hilbert Transform (HT) that is not restricted to frequency resolution and can, therefore, improve identification accuracy. In this paper, deriving from the vehicle response, the closed-form solution associated with bridge frequency removing the effect of vehicle velocity is discussed in the analytical study. Then a numerical Vehicle-Bridge Interaction (VBI) model with a quarter car model is adopted to demonstrate the proposed approach. Finally, factors that affect the proposed approach are studied, including vehicle velocity, signal noise, and road roughness profile.

IPC 거더 연속교의 실교량 내하력 평가 연구 (Load Bearing Capacity Evaluation of Continuous IPC Girder Bridge.)

  • 한만엽;황의승;진경석;강상훈;신재우
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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    • pp.475-478
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    • 2005
  • This study was performed to evaluate about load bearing capacity of continuos IPC Girder Bridge under and after Construction. This is Ichi-1 Bridge that is 2-40m span continuous bridge on a extension road through the Ichun and the Naesa. The result of static loading test to use a 25ton truck after construction, deflection ratio is 0.64 that is $35\%$ and average of response ratio is 0.48$\~$0.89 that is less than theoretical value. The result of dynamic loading test, the number of proper vibrations is 3.06Hz that is like theoretical value 3.61Hz, the modulus of impact is 0.235 that is bigger than specification 0.19. the load bearing capacity is minimum DB-40 that is so big value. In the result, continuos IPC Girder Bridge is safe in short period. we will evaluate long period behavior of continuos IPC Girder Bridge.

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PDA를 이용한 무선교량유지관리(MBMS) Application 개발 (Application of Personal Digital Assistant (PDA) for Mobile Bridge Management System (MBMS))

  • 이태식;이동욱;이성현
    • 한국철도학회논문집
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    • 제7권3호
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    • pp.223-231
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    • 2004
  • The accumulated BMS data have made it easy to make reasonable decision-making for bride maintenance and repair work. In the developing period of BMS, the bridge management was not easy due to the lack of understanding of BMS and low credibility of the data. In recent years, it has been possible to enhance the credibility of the data and to expand the application scopes of BMS with the efforts of Local Road Construction Offices. The reasonable decision making for bridge management can improve the performance of bridges under the practical constraints such as limited budget. It can then result in the reduction of bridge maintenance budget. This study provides the methodology for the application of mobile internet-based KOBMS for bridge management. The data flow for BMS is the most important factor for decision-making on budget allocation, and this study establishes the basic scheme of the data flow for BMS. The implementation of PDA for BMS may suggest a new paradigm of 'Mobile' in the field of construction management.

Modal parametric changes in a steel bridge with retrofitting

  • Walia, Suresh Kumar;Vinayak, Hemant Kumar;Kumar, Ashok;Parti, Raman
    • Steel and Composite Structures
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    • 제19권2호
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    • pp.385-403
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    • 2015
  • This paper presents the status improvement of an old damaged deck type rural road steel truss bridge through the modal parametric study after partial retrofitting. The dynamic and static tests on bridge were carried out as in damaged state and after partial retrofitting. The dynamic testing on the steel bridge was carried out using accelerometers under similar environmental conditions with same speed of the moving vehicle. The comparison of the modal parameters i.e., frequency, mode shape mode shape curvature, modal strain energy, along with the deflection parameter are studied with respect to structural analytical model parameters. The status up gradation for the upper and downstream truss obtained was different due to differential level of damage in the bridge. Also after retrofitting the structural elemental behavior obtained was not same as desired. The damage level obtained through static tests carried out using total station indicated further retrofitting requirement.

Impact factors of an old bridge under moving vehicular loads

  • Liu, Yang;Yin, Xinfeng;Zhang, Jianren;Cai, C.S.
    • Structural Engineering and Mechanics
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    • 제46권3호
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    • pp.353-370
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    • 2013
  • This paper presents a new method to study the impact factor of an old bridge based on the model updating technique. Using the genetic algorithm (GA) by minimizing an objective function of the residuals between the measured and predicted responses, the bridge and vehicle coupled vibration models were updated. Based on the displacement relationship and the interaction force relationship at the contact patches, the vehicle-bridge coupled system can be established by combining the equations of motion of both the bridge and vehicles. The simulated results show that the present method can simulate precisely the response of the tested bridge; compared with the other bridge codes, the impact factor specified by the bridge code of AASHTO (LRFD) is the most conservative one, and the value of Chinese highway bridge design code (CHBDC) is the lowest; for the large majority of old bridges whose road surface conditions have deteriorated, calculating the impact factor with the bridge codes cannot ensure the reliable results.

GIS를 이용한 교량재해관리시스템 개발 (Development of a Bridge Disaster Management System Using GIS)

  • 안기원;유환희;최윤수;신석효
    • 대한공간정보학회지
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    • 제7권2호
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    • pp.69-80
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    • 1999
  • 본 연구에서는 지리정보시스템을 이용하여 교량 안전 관리를 위한 교량재해관리시스템을 개발하고자 한다. 진주시에 위치한 교량시설물들에 대한 기본도, 도로망도, 교량위치도 등과 같은 여러 가지 도형 레이어 그리고 32개 교량에 관련된 속성자료들을 포함하여 데이터베이스를 구축하였다. Visual Basic 5.0 Language를 사용하여 여러 가지 교량안전관련 분석기능을 갖는 PC용 교량재해관리시스템을 개발하였다. 본 연구에서 개발된 교량재해관리시스템은 신속하고 효율적인 데이터검색, 파일관리, 교량제원의 검색과 관리, 교량관련 도면보기, 교통량조사의 검색과 관리, 교량점검결과와 보수상태의 검색과 관리 그리고 교량 안전등급의 평가의 기능을 가지고 있다.

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국내 도로교량 바닥판 열화모델 제안 및 교체 수요 예측 (Proposal of Domestic Road Bridge Deck Deterioration Models and Forecast of Replacement Demand)

  • 김진광;장일영
    • 한국구조물진단유지관리공학회 논문집
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    • 제21권4호
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    • pp.61-68
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    • 2017
  • 교량 바닥판은 대형 차량 및 제설제와 같은 다양한 환경 요인으로 인해 급속히 악화되는 부재이다. 한국에 건설된 교량의 수명이 길어짐에 따라 교량 바닥판의 교체 수요가 증가 할 것으로 예상된다. 다른 국가에서는 프리 캐스트 바닥판을 이용한 급속 교량 건설 기술이 열화된 교량 바닥판의 교체 수요 대응을 위해 적극적으로 사용되고 있다. 본 연구에서는 국내 교량 바닥판의 상태평가 데이터를 수집 및 분석하여 교량 바닥판 열화 모델을 제안 하였다. 또한 교량 규모의 관점에서 열화된 교량 바닥판의 미래 대체 수요를 예측하였다.