Stability Monitoring And Control Of Slope In Open Pit Mines Under Blasting Load

Deep-hole blasting is one of the important methods of open-pit mining in China.After long-term blasting operations,the slope rock mass suffers cumulative damage.Once the slope is unstable,it is more likely to cause accidents.In order to ensure the safe production of open-pit mining enterprises,the slope stability under blasting load has become an important research topic.The research was conducted on Mengku iron mine to reduce accidents.This work collected the blasting vibration data on the site,and analyzed it by combining on-site geological exploration reports and field investigation.The mainly obtained research contents and results are as follows:(1)Monitoring and analysis of blasting vibration dataThe blasting vibration data was collected on the site by intelligent blasting vibration monitors placed on the slopes.An analysis was conducted by combining with on-site geological conditions.The regression analysis of Sadowski's formula was performed to calculate the field parameters and attenuation coefficients of Sadowski's formula(k=269.535,=1.317).The vibration frequency of blasting operation is mainly concentrated between 10 Hz and 50 Hz.According to the regulations,the safe vibration speed shall not be greater than 12cm/s.The range of vibration speed of on-site blasting fully meets the above safety speed requirements.(2)Numerical simulation study of slope stability under blasting vibration loadRelevant literature were reviewed to understand thoroughly the on-site geological structure,and the slope-related geometry parameters.A three-dimensional model was established using FLAC3 D to simulate the distribution of force and slope deformation under the static state during the process of open-pit excavation.Based on the data of blasting vibration used as the dynamic response to the outside environment,the module stability under blasting vibration loading was analyzed.The stress distribution and displacement variation of the slope under dynamic load are obviously greater than that under static load,and the range of influence on the slope is wider,which indicates that the dynamic load is the important factor affecting the slope instability.(3)Based on the above research results,the vibration reduction measures of blasting vibration are proposed,followed by the slope treatment scheme for the open-pit mine.