Modal analysis of concrete gravity dam incorporating pre-stress condition along with soil–structure interaction
Abstract
Purpose
The fundamental period of the structure plays an important role in the seismic analysis. This study aims to analyze the modal response of dam, the two-dimensional (2D) FEM model is developed by using ANSYS 2022 R1 software.
Design/methodology/approach
To examine the optimized mesh size to achieve grid independence, the variable element size has been considered, and its optimal value is calculated using the technique of response surface optimization. Further, the effect of damping ratios of 5%, 8% and 10% is also considered for the free vibration analysis of the dam structure.
Findings
The results show that the natural frequencies of the dam decrease with a reduction in stiffness of the whole structure. Further, the effect of pre-stress conditions is analyzed and the study has proved that the natural frequency increases after considering the pre-stress as initial condition during modal analysis. Further, it is found that the damping has a substantial effect on frequency for higher modes of vibrations.
Research limitations/implications
The study only focused on modal analysis of the gravity dam, and this study’s results can be used further to evaluate the dynamic behavior of the dam including hydrodynamic conditions.
Originality/value
The finite element tool is used to evaluate the modal response of gravity dam incorporating pre-stress and damping ratio along with soil–structure interaction. Moreover, to the best of the authors’ knowledge, no earlier study has been conducted to evaluate the effect of damping and pre-stress conditions on the stability and natural frequency of the system.
Keywords
Acknowledgements
Acknowledgements. The authors appreciate Dr K. Nallasivam’s insightful and helpful comments throughout the manuscript-writing process. His willingness to contribute his time to this research work is definitely admired.
Funding. This study received no particular grant from any funding agency in the public, commercial, or not-for-profit sectors.
Author’s contributions. The authors significantly contribute to the idea and construction of the FE model, as well as to the collection, analysis and interpretation of data.
Availability of data and material. The data studied in this research were a re-analysis of previously collected data, which are freely accessible at each of the locations listed in the reference section.
Declaration of competing interest. The authors affirm that they have no past conflicts of interest that could have appeared to have an impact on the research presented in this study.
Consent to participate. Authors ensure and affirm that the manuscript shows our original work and has not been copyrighted, published or accepted for publication elsewhere.
Citation
Sharma, A. and .K, N. (2024), "Modal analysis of concrete gravity dam incorporating pre-stress condition along with soil–structure interaction", World Journal of Engineering, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/WJE-04-2024-0217
Publisher
:Emerald Publishing Limited
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