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Title |
Behavior of Truss Railway Bridge Using Periodic Static and Dynamic Load Tests
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Authors |
김진모(Jin-Mo Kim) ; 김건우(Geonwoo Kim) ; 김시형(Si-Hyeong Kim) ; 김도형(Dohyeong Kim) ; 김두기(Dookie Kim) |
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DOI |
https://doi.org/10.11112/jksmi.2023.27.6.120 |
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Keywords |
철도교; 의사 정적 시험; 동적 주행시험; 재하시험; 주행 열차; 충격계수; 고유진동수 Railway bridge; Static behaviors; Dynamic behaviors; Load test; Driving train; Impact coefficients; Natural frequencies |
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Abstract |
To evaluate the vertical loads on railway bridges, conventional load tests are typically conducted. However, these tests often entail significant costs and procedural challenges. Railway conditions involve nearly identical load profiles due to standardized rail systems, which may appear straightforward in terms of load conditions. Nevertheless, this study aims to validate load tests conducted under operational train conditions by comparing the results with those obtained from conventional load tests. Additionally, static and dynamic structural behaviors are extracted from the measurement data for evaluation. To ensure the reliability of load testing, this research demonstrates feasibility through comparisons of existing measurement data with sensor attachment locations, train speeds, responses between different rail lines, tendency analysis, selection of impact coefficients, and analysis of natural frequencies. This study applies to the Dongho Railway Bridge and verifies the applicability of the proposed method. Ten operational trains and 44 sensors were deployed on the bridge to measure deformations and deflections during load test intervals, which were then compared with theoretical values. The analysis results indicate good symmetry and overlap of loads, as well as a favorable comparison between static and dynamic load test results. The maximum measured impact coefficient (0.092) was found to be lower than the theoretical impact coefficient (0.327), and the impact influence from live loads was deemed acceptable. The measured natural frequencies approximated the theoretical values, with an average of 2.393Hz compared to the calculated value of 2.415Hz. Based on these results, this paper demonstrates that for evaluating vertical loads, it is possible to measure deformations and deflections of truss railway bridges through load tests under operational train conditions without traffic control, enabling the calculation of response factors for stress adjustments.
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