Ground vibration induced by high dam flood discharge has been reported to cause severe structure safety threats and environmental issues. In this paper, an evaluation and reduction approach for ground vibration using systematic and comprehensive studies is proposed. Based on the results of hydraulic physical model tests, the hydrodynamic excitation on the stilling basin plate (SBP) is analytically expressed as spatially variable harmonic loads by the three-dimensional least squares method. Afterwards, a theoretical model for the SBP–foundation coupled system is established and the vibration of SBP subjected to analytical hydrodynamic load input is calculated. The ground vibration is further evaluated through the numerical simulation regarding the SBP vibration as the input load. According to the prototype test result, it is found that the variation trend of evaluation results under different working conditions is consistent with the actual situation, which indicates the effectiveness of this evaluation approach. Furthermore, the sensitivity analysis of SBP physical dimensions to ground vibration is conducted, and an optimized design for SBP is presented as a result. The verification results indicate that ground vibration can be significantly reduced by applying SBP optimization.
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