Simulation study on the stability of open-pit mine slopes under blasting impact

Sun Lei; Du Xiaoxue; Ma Hongfa; Liu Chuanpeng; Yang Juntao

doi:10.16186/j.cnki.1673-9787.2023090032

Abstract：Objectives To investigate the dynamic response and stability evolution of slopes under blasting impact,field blasting monitoring tests were conducted on the slope of an open-pit mine in eastern Inner Mongolia.Methods A numerical slope model was established using ANSYS/LS-DYNA to simulate and ana-lyze the dynamic response of slope particles.The effective stress,vibration velocity,and displacement char-acteristics of the slope rock mass were examined.The safety factor of the slope under blasting impact was derived using the limit equilibrium method and quasi-static method.Results Under blasting,the peak stresses at monitoring points 1～4 were 1.09,0.55,0.23,and 0.15 MPa,with effective stress durations of 8,5,4,and 3 ms.The peak vibration velocities in the X-direction were 9.98,3.88,1.99,and 0.95 cm/s,and the residual deformations of the rock mass units were 0.001 80,0.000 90,0.000 55,and 0.000 40 cm.Conclusions The results indicate that the effective stress induced by blasting propagates into the rock mass,with its peak value decreasing over time and distance.As the distance from the blast center in-creases,the peak vibration velocity of slope particles decreases,and residual deformations in the plastic zone gradually diminish.The calculated safety factors under static conditions(1.35)and blasting condi-tions(1.05)both meet the specification requirements,indicating that the open-pit slope remains stable.These findings provide a reference for blasting construction in the open-pit mines.