Experimental Study On Shock Absorption Effect Of Chimney Blasting Demolition Of Shock Absorbing Embankment

In order to explore the shock absorption effect of shock absorption embankment to collapse and touchdown vibration of chimney demolition blasting.Combined with theoretical analysis,model experiment,numerical simulation and engineering application to do analysis.Through theoretical analysis,it is concluded that the shock absorption embankment can reduce the action time of the chimney body and the contact surface,reduce the impact force and impact energy of the main body of the chimney to the ground,and can effectively reduce the vibration of the ground.Based on the similarity theory,model experiments are carried out by changing the number of shock absorption embankment,laying position,height and material.The following conclusions are drawn:(1)With the increase of the number of shock absorption embankment,the effect of shock absorption is getting better and better.When the shock absorption embankment reaches 3,with the increase of the number of shock absorption levees,the increase of shock absorption effect is not obvious.When it sets on h2/,h4/3 and h8/7,the effect of shock absorption achieves the best.(2)With the increase of the height of the shock absorbing embankment,the effect of the shock absorption increases obviously.However,when the embankment reaches to 2.5m~3m,the effect of the embankment height is no longer obvious.(3)When the height is not equal,the shock absorption embankment will gradually increase along the direction of collapse.(4)The use of sand as a material for shock absorption embankment is the best in shock absorption,the second is the soft soil,and the worst is the concrete slag.With the increase of the number of shock absorption embankment,the difference of shock absorption effect is becoming smaller and smaller.At the same time,the chimney collapse model is established by using ANSYS/LS-DYNA,and the simulation results of vibration shock absorption of groundshock are set by different number of shock absorption embankment of chimney blasting demolition,and the conclusion of the model experiment is verified.It is also pointed out that when the number of damping dykes is 3,the damping rate can reach about 70%.This conclusion is consistent with the measured value of a practical blasting engineering.