Vibration Effect Of Moderate-long Hole Bench Blasting Based On Energy Principle

With the expansion of moderate-long hole bench blasting, the harm caused by engineer blasting increases accordingly, which is widely noticeed by blasting engineers, especially for blasting vibration. However, because of the instantaneity of blasting seismic wave, mutability, complexity of blasting medium and condition, and the diversity of structure type around the blasting area, it is still a very complicated project to study blasting vibration effect and control vibration harm. Through consulting a large number of related references, based on the research achievement of blasting vibration effect home and abroad, combining projects such as parameters optimization of charging and blasting in JinDuiCheng Open-pit mine, Science and Technology Plan Project(SY2010365)——mixing charging technology research of Mixing-loading Truck, blasting vibration monitoring of China United Cement Company Limited Nanyang branch, cutting excavation control blasting vibration monitoring of Yi-Ba High Speed near XiangXi River Bridge in Xingshan County China, blasting vibration monitoring of HuaXin cement(EnShi) Company Limited, blasting seismic wave band energy distribution character and elastic and elastic-plastic energy responses in blasting vibration, safety criterion and active control of blasting vibration were studied with field test, signal analysis technology, numerical calculation and structural dynamics theory.(1) Firstly, simulation tests show that it is very effective to use AOK time frequency distribution to analyze time frequency characteristic of blasting seismic wave. And blasting seismic wave frequence band energy under different conditions was studied by combining the AOK time frequency distribution and wavelet analysis method.(2) According to acceleration-time curve obtained by blasting vibration velocity signal directly with higher noise contribution, EEMD is used to de-noising treatment of blasting seismic wave. Simulation tests show that EEMD can overcome the defects of EMD model and keep the most of non-stationary character of signal inherent, which is suit to noise reduction of blasting vibration signal.(3) By analyzing the measured blasting seismic wave and the response spectrum analysis of blasting seismic wave with different peak of vibration velocity and dominant frequency and duration, the results show that the response spectrum analysis can not analyze the duration of blasting vibration wave.(4) To overcome the defect of response spectrum theory, elasticity SDOF energy responses equation was established and energy responses analysis was processed with measured blasting seismic wave, especially for input energy spectrum. The influences of three elements and structural inherent parameter to the input energy spectrum were analyzed.(5) Newmark-β time-history analysis method and bilinear restoring force model were used to analyze elastic-plastic SDOF structural energy responses mechanism under the action of blasting vibration, especially for hysteresis energy dissipation spectrum that can reflect structural plasticity accumulated damage. The influences of blasting seismic wave three elements, structural inherent parameters and restoring force model parameters to hysteresis energy dissipation spectrum were analyzed, and hysteresis energy dissipation spectrum under different blast conditions was also analyzed.(6) According to the two forms of structure destructed under the action of blasting seismic wave, a double standard criterion to blasting seismic wave harm which were the first time exceeding destructive max instantaneous input energy the and hysteresis energy dissipation reflected plasticity accumulated damage was put forward. And the scientificalness and reasonableness were tested by actural projects.(7) Double standard was used to control hazard effects of blasting vibration forwardly. Field tests were done using high precision digital detonator showed that different blast center distance would deduce the different overlap position of blasting seismic wave. Therefore, blast center distance should be considered when selecting reasonable decreasing vibration delay time. And reasonable decreasing vibration delay time at different blast center distance was seleced according to the structure breakage mechanism and engineering applications showed that it was feasible and effective.Moderate-long hole bench blasting vibration reseach based on energy analysis, was carried out. Research results provide theoretical foundation for confirming final multifactor safety criterions, which have important theoretical significance and engineering practical value for active control of blasting vibration effects.