Research On Dynamic Response And Stability Of Open Rock Slopes Under Blasting Vibration

During normal production period of deep concave open pit mine,there is frequent blasting,and the stability of slope under blasting vibration has been a hot issue for blasting workers.In this paper,the stability of the slope of the Beskuduk open-pit coal mine in Xinjiang under blasting is taken as the research object.The field blasting test is designed and the blasting vibration time history of a series of characteristic measurement points is measured.The analysis gives the blasting seismic wave propagation in the mining area Attenuation law;combined with the on-site situation,numerically simulated the stress wave propagation and evolution law of the slope under blasting conditions,and using the strength reduction method to calculate and analyze the stable state of the open-air rock slope under static and dynamic load conditions,and obtained the safety factor The regular results of safe blasting vibration speed and critical vibration speed provide practical reference for safe production blasting of other mines.The main research results:(1)Through the analysis of on-site blasting vibration data,it is concluded that the vibration speed range of general production blasting in other mines is 2.053?8.392cm/s;the vibration frequency is between 10?50Hz.The MATLAB software was used to linearly fit the data,and the actual vibration parameters K and ? on the site were 227.47 and 1.48,respectively,and the propagation law of blasting seismic waves consistent with the site engineering geology was obtained.(2)Using ANSYS/LS-DYNA software to simulate the blasting vibration of the slope,the stress cloud diagram within 100 ms after the explosive exploded in the rock mass,and the speed time curve and effective stress time curve of the slope measurement point.The numerical calculation is close to the measured data,and the three comparison errors are within the range of 10%,15%,and 20%,respectively;the stress values ofeach measuring point unit are 4.6MPa,0.997 MPa,0.962 MPa,0.313 MPa,and the stress value increases with the burst heart distance Keep decreasing.(3)Using the ANSYS finite element software and the finite element strength reduction method to analyze the stable state of the slope,the safety factors under static and dynamic loads are obtained.The results show that the safety factor of the slope when considering its own gravity is 1.67,which is in a stable state;when the slope is subjected to blasting load,the four sets of dynamic safety factors are 1.46,1.5,1.56,1.62,respectively,and the safety of the slope is derived The vibration speed is10.64cm/s and the critical vibration speed is 13.16cm/s,which provides theoretical support and practical guidance for strengthening the safe blasting production of other mines and preventing slope instability.