| With the rapid development of economic construction, blasting technology get a wide range of applications in railways, highways, mining, urban construction and water conservancy and hydropower projects, and application fields are constantly expanded. The blasting technology has penetrated into various fields of the national economy, and become one of the important integral means of construction. The engineering blasting brings enormous economic benefits, and meanwhile the blasting seismic effect become prominent, ranking first in the blast hazard for people’s attention.In this paper, the subject of 《YuShuPo Mine Shaft excavation blasting vibration monitoring and blasting vibration control technology》 has been studied, using a combination method of field measurement and numerical simulation. To make a detailed analysis of the impact of underground blasting vibration on the surface buildings, we can provide the technical basis of both preventing the surface buildings from damage and completing the construction on time. The main contents and conclusions are as follows:(1)Using UBOX-5016intelligent blasting vibration monitoring instrument measure the surface vibrating velocity in front and back of the tunnel face and the regression analysis is used to analyze the measured data by the least square method and obtained:The vibrating velocity attenuation law in the back of the tunnel face which has been excavated does not fitting the Sadaovsk formula, and the forecasting results are not informative. The vertical attenuation law in front of the tunnel face which is not excavated suits to the Sadaovsk formula, and there is a good correlation and the regression results is K=75.86, α=1.141. The attenuation law is:By this formula the velocity of blasting seismic wave in front of the tunnel face which is not excavated can be predicted.(2)Using wavelet packet method analyzes the trends of the energy percentage of different frequency bands, then found that the proportion of the total energy of the average energy of10Hz is more than95%, and are mainly concentrated in the40～70Hz frequency range, and shows that with the increase of blasting distance, the proportion of low frequency energy share has increased, the proportion of high frequency energy share continued to decline. Total energy and all the energy attenuation are consistent, obviously show in three regions. There is an attenuation equation with distance which is obtained by linear regression. ET=13.843R-0.6463By this formula we can fully characterize the energy decay trend with an increase of explosive distance and achieve the purpose of optimizing the real-time blasting parameters.(3)The process of cut-hole blasting is numerical simulated by the ANSYS/LS-DYNA software and found that the velocity of tunnel face which has not been excavated is bigger than which has been excavated. Therefore we should focus on monitoring and protecting the buildings in the back of the tunnel face when designing a blasting program. Comparing the simulation and measured data of the blasting seismic wave vibration and attenuation law, we know that its conclusions and features are consistent. So we can analysis and forecasting the characteristics of actual blasting seismic wave by the numerical simulation, and guide the actual blasting construction projects.(4)Simulating the effect of cut-hole crushing blasting, and found that not only the peak velocity conform the blasting safety Criterion, but also obtain well Blasting effect. Therefore it is reasonable to use duplex undercutting millisecond blasting and the delay time is set to50ms.(5) Eventually, the YuShuPo mine blasting excavation through a sewage treatment plant safety and on-time. It is proved that by monitoring the entire process of blasting and making detailed analysis of the data obtained, not only to improve production efficiency, but also to ensure the safety of the surrounding buildings. This method can provide a reference for this type of constructions. |
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