Structural Monitoring and Maintenance Volume 6, Number 2, June 2019 , pages 085-101 DOI: https://doi.org/10.12989/smm.2019.6.2.085 |
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The effects of scour depth and riverbed condition on the natural frequencies of integral abutment bridges |
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Reza Akbari, Saeed Maadani, Alireza Abedi and Shahrokh Maalek
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Abstract | ||
The effects of foundation scour depth and riverbed condition on the natural frequencies of a typical cross-river integral abutment bridge have been studied. The conventional operational modal analysis technique has been employed in order to extract the modal properties of the bridge and the results have been used in the Finite Element (FE) model updating procedure. Two tests have been carried out in two different levels of water and wet condition of the riverbed. In the first test, the riverbed was in dry condition for two subsequent years and the level of water was 10 meter lower than the natural riverbed. In the second test, the river was opened to water flow from the upstream dam and the level of water was 2 meter higher than the natural riverbed. The results of these two tests have also been used in order to find to what extend the presence of water flow in the river and saturation of the surrounding soil affect the bridge natural frequencies. Finally, the updated FE model of the bridge has been applied in a series of parametric analyses incorporating the effect of piles\'relative scour depth on the bridge natural frequency of the first four vibration modes. | ||
Key Words | ||
bridge; natural frequency; modal analysis; scour depth | ||
Address | ||
Reza Akbari: Office of Road Maintenance, Road Maintenance and Transportation Organization, Tehran, Iran Saeed Maadani: Department of Engineering, Takestan Branch, Islamic Azad University, Takestan, Iran Alireza Abedi: Department of Engineering, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran Shahrokh Maalek: School of Civil Engineering, University of Tehran, Tehran, Iran | ||