关键词: 大坝, 强震监测, 加速度, 傅里叶谱, 高程放大效应

Abstract: Strong earthquake monitoring is an important content of dam monitoring. The response of dam subjected to strong motion influenced by geomorphology, site condition and structure of buildings is different. We made a series of preprocessing (eliminating wrong point, baseline correction, bandpass filter) and conventional processing (digital integration and spectrum calculating) for the monitoring record via using the Seismosignal software; and then analyzed the correlation between parameters (the peak of acceleration and Fourier amplitude) and the dam height. The results of analysis revealed that 1) the amplification of peak acceleration and peak Fourier amplitude increased with the increase of elevation, and the amplification at the dam crest was obvious, so did the altitude effect caused by strong-motion; 2) the peak dominant frequencies of the Fourier spectrum in three directions (transverse, longitudinal and vertical) mainly concentrated around 1.5-6.5 Hz, but filtered in other frequency bands.

Key words: dam, strong earthquake monitoring, acceleration, Fourier spectrum, elevation amplification