Analysis Of Blasting Vibration Signal And Research On Slope Effect In Open Pit Mining

As an important way of energy production, open pit blasting mining occupies a large proportion in the way of coal resources exploitation in China. Bench blasting is widely used in the open pit mining with the simple construction, the large block rate and the foundation. But caused by blasting seismic effect, slungshot, noise and other issues will be on the surrounding built(structure) building materials, personnel and equipment damage. Especially many of our mine service life longer, with the increase of mining depth mine after the continuous renovation and expansion, nearly 40% of the open pit mine exist hidden trouble for the safety of the slope, slope effect has been an important research topic for scholars both at home and abroad, so the studies on the control of blasting seismic effect, the establishment of efficient, safe production environment to the engineering practice have important significance.At present, for research of blasting vibration effect is mainly through the blasting signal monitoring and analysis. Blasting signal as a complex typical unsteady, nonlinear signal. With fast, short duration characteristics mutation. For the analysis of blasting vibration signals. There are mainly Fourier transform, wavelet and wavelet packet analysis technology and HHT analysis method. The Fourier transform(Fourier transform) is the most basic technology. The signal analysis has been widely used in the field of steady and linear signal analysis; wavelet and wavelet packet analysis technology is mature. The non steady signal time-frequency transform has obvious advantages. But it is still based on Fourier transform. It has obvious limitations; the HHT analysis method is a kind of new analysis method. Not only can adaptively depict local signal time-frequency characteristics. It can further analyze the energy change of the local application has. Good prospects. In addition, the amplification effect of the slope has been the focus of the study, and the safety evaluation of the building(structure) should be evaluated from the aspects of vibration velocity, vibration frequency and energy.Based on the HHT theory, by using the MATLAB software of Hequ mountain coal Open-pit Bench Blasting vibration signal measured is studied as follows:(1) EMD decomposition of the signal obtained after the IMF component can be very good to see the main vibration frequency of different frequency borehole blasting in about 10~15Hz. and the natural frequency of earthquakes closer to the.Hilbert spectrum can well depict the signal in the time-frequency domain on the amplitude of energy;(2) to simulate and analyze the frequency by using the least square method. And the frequency of different frequency built(structure) of buildings caused by the amplification coefficient for calculation and analysis. The results showed that with the increase of explosion source measuring point the frequency of the whole distance. Low frequency appears trend. And in the rock on the measured frequency than the soil medium. When the frequency of high buildings and the similar frequency generated when the amplification effect is more obvious;(3) Will signal instantaneous energy respectively, speed and frequency fitting analysis. And of different frequency band energy were calculated. The attenuation law of;(4) based on HHT EMD recognition method and instantaneous energy recognition method of millisecond blasting delay interval were identified. Show that the instantaneous energy identification method can better identification detonator loading time. And the parameter optimization has reference significance.According to the slope effect of blasting vibration. The principle of elevation effect is studied. Mainly the whiplash effect and group effect and interface slope effect of the result. The 66 groups of data measured by MATLAB were analyzed. The traditional Sa Rodolfo J Ki empirical formula. Based on the improved formula of reference the dimensionless method to get the height parameters. And the two formula of error is analyzed. The results show that the amplification effect of the improved formula can better reflect the elevation of the elevation of the new parameter; introducing elevation amplification effect coefficient. Combined with the measured data for comparative analysis showed that the elevation in 25~60m.. The horizontal distance is more obvious in 200~400m elevation effect.