Study Of Slope’s Blasting Safety Evaluation Method Based On Seismic Wave Energy

With extensive application of blasting techniques in all fields of national economy, the vibration damage of blasting construction gets more serious, and it gradually become one of the main damages affecting the surrounding environment security. Although domestic and foreign researchers have carried out a lot of theoretical and practical research on the blasting vibration and achieved some results. But because of the blasting seismic waves’ the randomness, fuzziness and uncertainty, these characteristics have greatly increased the difficulty of blasting vibration analysis and the control of blasting vibration effect. Therefore, the research on the blasting vibration is still a complicated and arduous task. In mine, the blasting vibration not only can reduce explosives’ effective utilization rate, but also affect the stability of slope and surrounding buildings, even directly restricts long term development of mining enterprises. Based on this, combined with the Dagushan Iron Mine, Donganshan Iron Mine and Qidashan Iron Mine, through formulated schemes of blasting vibration and operated instrument to survey date, then applied the wavelet analysis method and Hibert-Huang wavelet analysis to study on the energy band distribution of blasting vibration signal.The main contents and conclusions are as follows:(1) According to testing scheme designed in three mines, via operating instrument on the field, then export date and preliminarily analyze. At the same time, using BLASTER’S RANGER II explosive high speed camera analyzes the blasting effect, the transformation of muckpile and blasting dust and the situation of blasting vibration, in order to obtain the trend of energy transformation after explosive blasting. Finally, it calculates the parameters of Sadov’s formula, and obtains prediction formula.(2) Via the analysis of energy distribution characteristic in different frequency bands on the basis of wavelet transform, it can obtain that the main components of blasting vibration signal are concentrated in the middle and high frequency range, but the components of low frequency section is very small. Although the energy in the middle and high frequency range is relatively large, but in the regional distribution, it shows a great uneven situation, even in a large area again appears some local "sub centers".(3) By using the HHT analysis method, it can obtain three-dimensional energy spectrum, instantaneous energy spectrum and the proportion of frequency band energy in three schemes. It intuitively shows the situation of energy distribution at different positions and reveals the attenuation law of seismic wave energy in the course of propagation.(4) Because of the limitation of single index evaluation method, it puts forward a comprehensive method-TIE(Total Input Energy) that peak vibration speed, frequency, duration and cumulative effect are fused together. At the same time, it establishes TIE blasting vibration safety evaluation index on the basis of mine. Using this index to analyze measured signal of the three mine. By contrasting with actual survey, it evaluate the applicability of TIE index. The index is: when TIE<0.9, blasting vibration is not harmful to mine’s slope; when TIE≥0.9, blasting vibration will probably constitute a hazard to mine’s slope.