Abstract: This research was to reveal the variation regularity of observed dam behavior in the frequency domain, and to make quantitative analysis on the causes of variation. With a gravity dam as a case study, we analyzed the spectrum of monitoring data sequence of dam behavior in service, and established a model to analyze the coherence relation between effect quantity and influence quantity from the aspect of system identification. Through comparison between the results of time-domain analysis and frequency domain analysis of prototype monitoring data sequence, we confirmed the feasibility and validity of this approach.

Key words: dam, monitoring data, spectrum analysis, coherence analysis