Kömürhan Highway Bridge is a reinforced concrete box girder bridge located on the 51st km of Elazığ-Malatya Highway over the Fırat River. Because of the fact that the Kömürhan Bridge is the only bridge in this part of Fırat, it has major logistical importance. So, this paper aims to determine dynamic characteristics such as natural frequencies, mode shapes, and damping ratios of the bridge using experimental measurements and finite-element analyses to evaluate current behavior. The experimental measurements are carried out by ambient vibration tests under traffic loads. Due to the expansion joint in the middle of the bridge, special measurement points are selected and experimental test setups are constituted. Vibration data are gathered from the both box girder and bridge deck. Measurement time, frequency span, and effective mode number are determined by considering similar studies and literature. The peak picking method in the frequency domain is used for the output-only modal identification. An analytical modal analysis is performed on the developed two-and three-dimensional finite-element model of the bridge using SAP2000 software to provide the analytical frequencies and mode shapes. At the end of the study, dynamic characteristics of the Elazığ and Malatya parts of the bridge obtained from the experimental measurements are compared with each other and transverse effects on the bridge are determined. Also, experimental and analytical dynamic characteristics are compared. Good agreement is found between dynamic characteristics in the all measurement test setups performed on the box girder and bridge deck and analytical modal analyses.
The main purpose of this study is to examine the advantages and disadvantages of the Kömürhan bridge, built with natural aggregate concrete in Elazig, in terms of mechanical, environmental, and economic properties if certain ratios of recycled concrete aggregate (RCA) were used. For this purpose, a detailed laboratory study was designed, and concrete samples were produced, all‐natural, all‐recycled, and both recycled and containing natural aggregates. Different water‐to‐cement, aggregate‐to‐cement, and recycled concrete aggregate‐to‐total aggregate ratios were considered for the mixture designs of these samples, and the fresh and hardened concrete properties of these samples were determined. Then, statistical analyses were made using the response surface method, and numerical models were developed to predict the fresh and hardened concrete properties with high accuracy. Mixtures containing RCA, which have the same fresh and hardened concrete properties as the fresh and hardened concrete properties of the Kömürhan bridge, which was selected as an example structure by using these models, were determined for optimization purposes. A detailed environmental and economic comparison of the optimization and reference mixtures was made. While making environmental assessments, energy consumption, global warming potential, waste generation, and abiotic depletion were considered. It was seen that the optimization mixtures were more economical and more environmentally friendly than the reference mixture. As a result of this study, it was predicted that the use of RCA in buildings constructed using large amounts of concrete could provide significant environmental and economic advantages and was exemplified by the Kömürhan bridge.
Cable-stayed bridges are flexible and complex structures. Impact-induced vibrations may play an important role on the behaviors of the structural elements. Many efforts have been devoted to clarifying the experimental static and dynamic responses of cable-stayed bridges. However, experimental dynamic responses of structural elements of cable-stayed bridges under impact-induced vibrations have not been addressed widely in the literature. The paper focuses on the real experimental dynamic behaviors of cables, deck, and pylon in cable-stayed bridges under impact-induced vibration effects due to fully loaded trucks passing over a bump positioned on the deck center. The tests have been implemented on the new Kömürhan cable-stayed bridge under the passage of two-40 ton trucks. The thickness of the timber bumps and speed of the trucks are selected as 50mm and 30km/h, respectively. The dynamic responses of the structural elements have been recorded using load cells, 2D and 3D accelerometers. Forces, accelerations and frequencies of the main and back span cables, and acceleration responses of deck and pylon recorded with and without impact effects are evaluated and compared with each other. Significant impact-induced amplification ratios on the responses of the main and back span cables, deck and pylon are observed on the selected bridge.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.