Study Of The Blasting Damping Theory And The Design Method Of Multi-row Drilling Holes

Damping holes, as an effective control blasting technology, have been applied in theengineering, and have achieved great economic and social benefits. Because of thediffraction by damping holes,blasting seismic wave propagation path will change andthe strength of a wave will be weakened whenmeeting the damping holes.Atpresent,the research onthedamping effect of damping holesis limited, which staying thestage of qualitative analysis, and the design methods of damping holes are almost at thelevel of blank.This makes the related applications of damping holes in practicalengineering being mainly depending on the experience, lacking theoretical guidanceand a complete design method.The paper intends to analyze the change law of main influent factors by meansofthe analytical solution of damping effect, the experimental study and numericalanalysis. The main factors that influencingdamping effect queue by sensitivityanalysis. The main research results are as follows:1. Through analyzing the diffraction of single hole by wave function expansionmethod, the analytical expressions is set up. The results show that damping effect ofsingle hole increases with the increase of the diameter, and increases with thedecrease of the poisons ratio.2. Based on analyzing the experiment data of one row damping holes and doublerows damping holes, the peak velocity formula is established. Results show that aftersetting up damping holes, attenuation amplitude of horizontal velocity peak is largerthan vertical direction, horizontal spectrum shapechanges, the peak frequencydecreases, and vertically spectrum is almost unaffected.3. According to experimental study conditions, a numericalanalysis model was builtup. The numerical test method and scheme is determined,two methods of applying theblasting load are compared, and theexperimental results verify the adaptability ofnumerical model. Results show that attenuation law of blasting seismic wave’smainvibration phase is consistent, whichgenerated by two loading modes. Test result errorbetween numerical test and experiment is within16%. 4.Through the analysis of the results of numerical experiment,the pore diameter,super digging depth, critical pitch and pitch, row number are determined as the maininfluent factors of damping effect of damping holes. Results show that the value ofdamping effect increases with the increase of the pore diameter, with increase of superdigging depth, with increase decrease of critical pitch and pitch. The row spacing haslittleinfluence upon the damping effect.5. Throughsensitivity analysis,the main influence factors of damping effect arequeuing, the relationship between the damping factor of the maximum peak values ofblasting vibration velocity and the damping holes’ diameter, spacing, blast centerdistance and row spacing is set up, and its reliability is verified through results ofexperiment and engineering cases in documents. Results show that test result errorbetween the fitting formula calculation results and experiment is within20%.