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Title |
Critical Strengthening Ratio of CFRP Plate Using Probability and Reliability Analysis for Concrete Railroad Bridge Strengthened by NSM
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Authors |
오홍섭 ; 선종완 ; 오광진 ; 심종성 ; 주민관 |
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Keywords |
콘크리트 철도교 ; NSM 보강공법 ; MCS ; 목표신뢰도 ; 임계보강비 concrete railroad bridge ; NSM strenghening technique ; MCS ; target reliability index ; critical strengthening ratio |
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Abstract |
The railroad bridges have been usually experienced by vibration and impact in service state. With this reason, it is important that the effective strengthening capacity should be considered to resist the kind of service loading. In this study, NSM strengthening technique is recommended for the concrete railroad bridge because of its better effective resistance for dynamic loading condition and strengthening cost than the conventional externally bonded strengthening using fiber sheet. However, to widely apply NSM method for the concrete railroad bridge, it needs that the strengthening ratio has to be reasonably evaluated with geometrical and material uncertainties, especially for the concrete bridge under long-term service state without the apparent design history and detail information such as concrete compressive strength, reinforcing ratio, railroad characteristics. The purpose of this study is to propose the critical strengthening ratio of CFRP plate for the targeted concrete railroad bridge with uncertainties of deterioration of the structures. To do this, Monte Carlo Simulation (MCS) for geometrical and material uncertainties have been applied so that this approach may bring the reasonable strengthening ratio of CFRP plate considering probabilistic uncertainties for the targeted concrete railroad bridge. Finally, the critical strengthening ratio of NSM strengthened by CFRP plate is calculated by using the limit state function based on the target reliability index of 3.5.
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