露天矿爆破时砖混结构房屋振动响应的模态参数识别与爆破减振方法

为确保矿区周围房屋安全，采集矿区周围单层砖混结构房屋的爆破振动信号，根据运筹模态分析（operational modal analysis，OMA）相关理论，运用希尔伯特黄变换（Hilbert Huang transform，HHT）和小波包分解的方法对爆破地震波信号进行了分析。确定了单层砖混结构房屋地基与墙壁爆破振动信号的各阶固有频率，得到了不同振动方向各阶的固有模态函数（intrinsic mode function，IMF）贡献率。结果表明:地基与墙壁的IMF贡献率存在明显差异；地基高频序列IMF贡献率较高，墙壁的低频序列IMF贡献率较高。对墙壁测点数据进行分析可知:随着墙壁高度的增加，低频段，低频能量逐渐减小；高频段,高频能量逐渐增加。改变装药结构与间隔起爆时间，可使爆破地震波出现峰谷叠加现象，从而减小爆破振动效应，降低质点的振速。

Modal Parameter Identification of Vibration Response of Brick-Concrete Building and Blasting Vibration Reduction during Blasting in Open Pit Mine

In order to ensure the safety of buildings around the mining area, blasting vibration signals of singlelayer brick-concrete houses around the mining area were collected, and according to the relevant theory of OMA (operational modal analysis), the collected blasting seismic wave signals were analyzed by HHT (Hilbert Huang transform) and wavelet packet decomposition methods. Natural frequencies of the blasting vibration signals of the ground foundation and wall of the single-layer brick-concrete house were analyzed, and IMF contribution rates of the various stages in different vibration directions were determined. Results show that IMF contribution rates of the ground foundation and that of the wall are significantly different. IMF contribution rate of the high frequency sequence of blasting seismic waves on the ground foundation is high, but IMF contribution rate of the low frequency sequence of blasting seismic waves on the wall is high. Data of the measurement points on the wall show that, as the height of the wall increases, the low frequency energy gradually decreases in the low frequency band, while the high frequency energy gradually increases in the high frequency band. By changing the charge structure and interval initiation time, peak-valley superposition effect of the blasting seismic waves could appear, the blasting vibration effect can be reduced, and particle vibration velocity could also be reduced.