Model Construction And Model Test Of Rock Movement Velocity In Bench Blasting

Bench blasting is widely used in mine production.In the process of blasting construction,due to the lack of research on the motion law of broken rock,it is easy to produce problems such as blasting flyrock and poor throwing effect.In order to further study the influence of the change of blasting parameters on the rock motion rule of bench blasting,using the theoretical and numerical analysis methods to establish the model of the velocity distribution of broken rock,and according to the similarity theory to carry out the blasting test of bench model,to respectively study the impact of the explosive consumption,the minimum resistance line and decouple coefficient to the motion law of broken rock.The explosive consumption experimental study of the bench blasting model shows that:under the action of explosive energy,the broken rock on the free surface of the bench makes the bulging movement,and the bulge contour is approximately symmetrical distribution with the"convex"shape.When the explosive consumption varies within the range of 0.27kg/m³ to 0.51kg/m³,the bulge movement time increases with the increase of the explosive consumption as a power function.At the same time,under the action of detonation gas and collision between broken rock,the particle in the center the center of bulge experienced the process of acceleration n-deceleration-acceleration-deceleration-acceleration,and the interaction between rocks was weakened.There is a critical explosive consumption of 0.46kg/m³,which makes the throwing velocity increase sharply,and the maximum velocity of broken rock satisfies the exponential function increasing relation with the increase of explosive consumption.By comparing the calculated results with the experimental results,it can be seen that the calcution model is reasonable and feasible.The maximum throwing distance of broken rock increases as a power function with the increase of explosive consumption,and the corresponding throwing Angle decreases with the increase of explosive consumption.The minimum resistance line experimental study of the bench blasting model shows that:when the minimum resistance line varies within the range of 12cm to 20cm,the bulging movement time satisfiest=0.07W²-1.09W+18.94 with the increase of the minimum resistance line.The increase of the minimum resistance line greatly enhanced the interaction between the rocks,while the impact of detonation gas on the velocity of the bulging center particle was weakened.With the increase of the minimum resistance line,the maximum throwing velocity satisfies v=8.14（w³/Q）^-0.25.By comparing the calculated results of the model with the experimental results,it can be seen that the throwing velocity distribution model is reasonable.With the increase of minimum resistance line,the maximum throwing velocity of broken rock shows an obvious power function decreasing relation,and the corresponding throwing Angle is a quadratic function increasing relation with the increase of minimum resistance line.The decoupling charge experimental study of the bench blasting model shows that:when the decoupling coefficient varies from 1.25 to 3.375,the bulging movement time satisfies t=0.79n²+1.44n+11.53 with the increase of the decoupling coefficient.Under the condition of decouple coefficient,the increase of decouple coefficient enhances the interaction between the broken rocks,and weakens the influence of blasting gas on the motion velocity of the center particle,so that the bulge center particle moves at variable speed.With the increase of the decoupling coefficient,the maximum throwing velocity satisfies v=10.97（n-1.20）^-0.23,and the corresponding maximum throwing distance shows an obvious power function decreasing relation.The experimental results show that the throwing velocity distribution model is also reasonable and feasible under the condition of decoupling charging.The throwing Angle corresponding to the furthest throwing distance of broken rock decreased exponentially with the increase of decoupling coefficient,satisfies t=1121.81e^-3.36n+56.29.The grey relational degree analysis shows that the throwing velocity of the broken rock is the most sensitive to the explosive consumption,followed by the minimum resistance line and decouple coefficient.