关键词: 爆破地震响应, 井下平洞, 小波分析, 频谱, 能量比例

Abstract: In order to discuss the characteristics of blasting vibration response of tunnel structure near ground surface under open-pit mine blasting, we collected a large amount of blasting vibration response signals of the tunnel structure by arranging measuring points on the underground tunnel vault and the ground along the orbit direction. Furthermore, we discuss the distribution characteristics of frequency spectrum and energy of tunnel based on wavelet analysis and fast fourier transform (FFT) algorithm. The results indicate that, 1)frequencies in tunnel the vault and the bottom of tunnel are larger than those in other positions, mainly in the range of 10-312 Hz; 2) the band of the main frequency accounted for large proportion of total energy; 3) the frequencies in vertical direction are lower than those in horizontal direction, and main frequency in vertical direction doesn’t change much with distance, but variation of main frequency in horizontal direction is obvious; 4) as for velocity response of tunnel structure in vertical direction, signal frequency at tunnel vault is lower than that at bottom of the tunnel, which should be paid more attention to.

Key words: blasting vibration response, underground tunnel, wavelet analysis, spectrum, energy proportion