Inversion algorithm for the whole prototype dynamic displacement field of a high arch dam based on limited measuring points

Abstract

The mean square deviation (MSD) of an arch dam dynamic displacement response during a flood discharge period is an important indicator used to evaluate the vibration intensity. The whole distribution of the MSD of the dynamic displacement response reflects the whole dynamic displacement field. Inversion of the whole dynamic displacement field of the arch dam based on limited measuring points is of significance. In this study, the Ertan arch dam was used to propose an inversion algorithm for the whole prototype dynamic displacement field of the arch dam. First, inversion theory of flow-induced vibration response for the arch dam is introduced. Second, the arch dam prototype vibration test under flood discharge excitation is conducted to determine the dynamic displacement response of limited measuring points. Third, the full-scale finite element model of the Ertan arch dam is set up to conduct modal analysis, and the first nine modes are cutoff to extract the modal parameters for the inversion of equivalent excitation source load spectra. Finally, the whole dynamic displacement field of the arch dam is calculated by flow-induced vibration response positive analysis based on the equivalent excitation load spectra. Inversion results show that the whole arch dam dynamic displacement field is obtained through only seven dynamic displacement response measuring points arranged on the crest of the dam. Simultaneously, the inversion and measured values are in good agreement. This method provides a novel technique to reasonably evaluate the high arch dam during the flood discharge period.