Research On The Propagation Law And Dynamic Effect Of Blasting Vibration In Jingang Sand And Gravel Mine

Blasting is the main way of open-pit mining.With the continuous development of mining,the harmful effects of bench blasting in some open-pit mines cause damage to the surrounding buildings.In order to control the impact of blasting vibration on the surface buildings around the mine,this paper,based on the National Natural Science Foundation Project(51664007),takes the blasting operation of sandstone mine of Anshun steel and Concrete Co,Ltd.as the actual research object.Through the blasting vibration test,the propagation law of blasting seismic wave and the finite element numerical simulation analysis are studied.The attenuation law of blasting seismic wave's vibration velocity and the change of main vibration frequency with the increase of blasting center distance under the blasting load of different bench height are analyzed;By comparing the peak vibration velocity with the maximum safe vibration velocity,the dynamic effect characteristics of the surface buildings caused by blasting and the dynamic effect characteristics of the surface buildings under blasting are studied.The internal relationship between the peak vibration velocity and the stress field is discussed,and the damage of the buildings caused by the harmful effect of blasting operation is judged.The main research results are as follows:(1)Based on the experimental research,the radial,tangential and vertical peak vibration velocity decreases with the increase of elevation and horizontal distance;with reference to the Sadovsky formula and the prediction formula of the Yangtze River academy of Sciences,and combined with the least square method,the regression analysis of the experimental data is carried out,the more suitable vibration prediction formula for the blasting operation in this mine is modified,and the empirical formula for peak vibration velocity attenuation is established,which will be helpful for the future The prediction of blasting vibration provides guidance.(2)The attenuation coefficient K and ? increase gradually with the increase of the height difference;the tangent attenuation coefficient K and ? decrease with theincrease of the elevation due to the influence of the slope lithology and geological structure of the step with the height difference of 30m-40m;the elevation coefficient ?decreases with the increase of the height difference except for the 30-40 steps.(3)The horizontal shear stress and the vibration velocity decrease with the increase of the horizontal distance of the blasting center.There is a quadratic exponential relationship between horizontal shear stress and vibration velocity.(4)In engineering,the maximum allowable safe vibration speed calculation can be used to obtain the allowable peak shear stress.It can be determined whether the shear stress inside the building exceeds the allowable shear strength under the action of blasting;Destruction,etc;Provides reference for blasting vibration control,hole network parameters and design indicators.