Blasting Vibration Analysis, Applied Research, Based On Wavelet And Wavelet Packet Transform

With the wide application of blasting technology to mining industryand civil engineering, people have been paid more and more attention tomitigating harm of blasting vibration to both of buildings and importantsurroundings near to the site of blasting operation. Correspondingly, a lotof investigation on mitigating vibration complaint has been carried out bythe researchers all over the world. On the basis of systematically studyingreferences in blasting signal processing, a series of in-situ blastingvibration waves had been tested according to the researching contents of aproject for the Tenth Five-year Plan of National Key Technology ofResearch and Development. Further, the wavelet and wavelet packettheory were used to process blasting vibration waves, and both of blastingvibration signal de-noising and change in energy spectrum of vibrationsignals with related factors were studied deeply. The main conclusions ofthis thesis are as follows:(1) Based on the principle and algorithm of the wavelet, fourwavelet bases of db5, db8, sym7, and coif3 were selected to decomposeblasting vibration waves, and to rebuild them. In comparison with theerror between the original signals and corresponding rebuilt signals, itwas found that sym7 is the best wavelet base for blasting vibration signalprocessing.(2) The wavelet threshold de-noising method and wavelet packetthreshold de-noising method were used to de-noise blasting vibrationwaves. The results showed that these two de-noising methods work wellin de-noising vibration waves, and in enhancing the reliability andaccuracy of vibration signals. Comparatively, the better de-noising resultof vibration signals might be obtained by wavelet packet thresholdde-noising method.(3) Also, the wavelet packet analysis technology was usedinvestigated into change in energy spectrum of blasting vibration waveswith the distance between explosion centers and monitoring points where the vibration waves were recorded, and with the maximum amount ofexplosives timing detonation. The results showed that under the specifiedground condition, the intensity of blasting vibration is strongly influencedby the maximum amount of explosives and the distance between theexplosion center and monitoring point. With the increase in both of themaximum amount of explosives and the distance between the explosioncenter and monitoring point, the main frequency of vibration wavespectrum shifts toward lower frequency band.(4) The related techniques, used to mitigate the blasting vibrationharm to close building and surroundings, were analyzed. Aiming atfurther mitigating blasting vibration complaints, the relative opinionswere given.