Seismic Wave Propagation Law Of The Bridge Pile-well Blasting And Application

With the rapid development of economy in our country, the scale of transportation pipeline such as natural gas pipeline and oil pipeline is becoming more and more large. For reason of this,new projects such as highway and railway may be cross or adjacent to the pipeline, then the new construction will inevitably have a negative impact on the pipeline. Especially if the projects use blasting,the harmful effect of blasting such as blasting vibration and blasting slungshot may cause incalculable harm in the pipeline.Therefore, in this kind of project, in order to ensure the safety of adjacent pipelines, to carry out the research about related laws of blasting damage and the control method has important significance.Based on the blasting construction of Red Spring Village 3# Bridge bridge pile-well located in Rongcheng-Wuhai highway, this paper mainly used field test,theory analysis and BP neural network methods to study seismic wave propagation law of the bridge pile-well blasting and its application in practical engineering, then mainly get the the following conclusions.Used the methods of field test result analysis and p-wave wave propagation theory analysis to study the surface propagation law of radial and vertical vibration velocity in bridge pile-well blasting, it was found that with the increase of the distance from the edge of the pile-well, the attenuation law of the vertical and radial blasting vibration velocity is different; meanwhile, when the horizontal distance from the pile-well edge is less than and greater than about 7m, the size relationship between the vertical and radial blasting vibration velocity is different.The field test results analysis showed that if the blasting parameters is unchanged, the size relationship of vibration velocity generated by cut holes and surrounding holes is different under the different depths of pile-well; meanwhile,with the increase of pile-well depths, the change law of vibration velocity generated by cut holes and surrounding holes is different.Set up 15 groups of training(fitting) samples and 5 groups of test samples by using the blasting parameters and vibration monitoring data in the projectfield, then respectively used the BP neural network, Elevation correction formula and Sodev,s empirical formula to forecast the vibration velocity of the bridge pile-well blasting, and the results showed that the average relative errors of the BP neural network, Elevation correction formula and Sodev,s empirical formula were 7.90%, 24.30% and 27.68%, respectively.Based on the law of the experimental results, put forward a zoning control method of blasting parameter according to different horizontal distances and depths of the pile-well, then apply this method in pile-well blasting engineering of Red Spring Village 3# Bridge which is close to the Shanxi-Beijing natural gas pipeline, the results show that the method can not only effectively ensure the safety of adjacent buried gas pipeline, but also greatly improve the efficiency of the pile-well construction.