Research On The Propagation Law And Prediction Of Blasting Vibration In Stope Of Chuanyandong Mine

For control of blasting vibration on slope,this paper based on the national natural fund project(51774101,51664007),as the urn phosphate rock in caves ore block stope blasting practice as the background,on the basis of existing research,the combination of theoretical analysis,field test and numerical simulation,the method of single ring is studied under the largest quantity of 204 kg spread regularity of blasting vibration velocity,the main frequency,and put forward the space b-spline prediction method of blasting vibration signals,and establish a numerical model to study the dynamic response characteristics of rock mass under blasting,explore its inner connection of peak velocity and the stress field,The main research results are as follows:(1)Based on the field test of vibration monitoring,it is found that the peak vibration velocity increases with the elevation and horizontal distance,attenuates faster near than far,and slightly attenuates from the edge of steps to the inside;Typical elevation amplification effect appears in the vertical direction.The amplification at the edge is 1.09 times,and the amplification at the middle is 1.03 times,both of which are larger than the inner side.However,the overall peak vibration velocity does not show amplification effect,but shows an overall attenuation trend.The main frequency decreases with the increase of elevation and horizontal distance.The inner main frequency is generally larger than the edge and the middle,and the dispersion is larger,less than 100 Hz.(2)Based on b-spline theory,combining with the characteristics of blasting vibration signals,the 3 d and 3 B spline curve is put forward the steps of the blasting vibration prediction method,and field test,the method can predict the blasting area designated point(different height and level distance)peak velocity and the main frequency of the predicted results keep better consistency with field test.(3)The dynamic response characteristics of rock mass were studied based onls-dyna numerical simulation,and it was found that the vibration velocity response was consistent with the field measurement,the shear stress response was consistent with the vibration velocity,and it attenuated strictly with the increase of elevation and horizontal distance.The inner stress was greater than the middle and the edge,and there was a quadratic exponential relationship between the peak shear stress and the synthetic peak vibration velocity.(4)The results of engineering examples show that the propagation law of blasting vibration and the allowable peak shear stress can be mastered through the study of b-spline prediction and dynamic response characteristics,which provides a reference basis for the control and prediction of bench blasting vibration.