According to the blasting excavation condition of a vertical chute in a large open-pit mine,the forward excavation method of"central pilot hole+blasting expansion excavation"is used to carry out blasting operation,and smooth blasting technology is adopted to control the forming effect of the pass.By studying blast hole network parameters,charging structure and delay mode,combined with the numerical simulation prediction results,the blast hole network parameters are optimized and adjusted.The results show that the minimum resistance line ranges from 0.9 to 1.0 m,the distance between the auxiliary holes is between 0.94 and 1.07 m,and the cracks between auxiliary holes are basically completely penetrated,which can effectively ensure the uniform rock crushing and improve the footage efficency.Fine blasting construction control measures are adopted during on-site blasting operation.Aiming at soft rock stratum,the footage and smooth blasting parameters are properly adjusted,the charging structure and dosage of smooth blasting are improved,the disturbance of surrounding rock is reduced,and the forming quality of wellbore section is ensured.
万方数据
维普
