Numerical Simulation Research Of Deep-Hole Blasting Parameters Optimization And Safety Control In Tonglushan Mine Underground Stopes

The paper based on the research program of underground deep-hole elaborate blasting technology in Tonglushan mine. It adopted numerical simulation experiment for research method, made study on the key blasting technologies in blasting parameters optimization and safety control that deep-hole blasting stope existing. Here were the main content of the paper and its research results:(1)Based on properties of rock mass and parameters of explosive, author used ANSYS/LS-DYNA to simulate the process of rock blasting crack propagation under different pore size and charging construction, and analyses the mechanism of rock crack generating. It is obtained the radius of rock crushing zone and fractured zone. The result indicated that, Non-coupling charging construction can reduce the excessive consumption of blasting energy in the crushing zone and reduce the size of the crushing zone. In addition, it has a positive effect on the extension of fracture zone. Comparing with large-hole blasting, Small-hole blasting’s inflection point of the PPV curve becomes more obvious. It is recommended that use small-hole non-coupling charge construction to control the blasting vibration in engineering fields.(2) It used ANSYS/LS-DYNA to simulate26types blasting numerical models, in order to determine the best network parameters of deep-hole blasting stope. Simulation results show that, using3cartridge non-coupling charge construction, when blast hole are165mm,127mm and110mm in diameter, the best network parameters are3.0m×2.6m、2.6m×2.6m and2.4m×2.2m. using2cartridge non-coupling charge construction, when blast hole are165mm in diameter, the best network parameters are3.0m×2.6m.(3) It used ANSYS/LS-DYNA to simulate10types blasting numerical models in different ways of initiation, in order to control maximum explosive charge fired at the same time. The research indicated that, when the total explosive charge is kept constant, using the short-delay blasting method can reduce the explosive vibration efficaciously. Through analyses the monitoring data of blasting numerical simulation by the unary linear regression method, the Sadaovsk formula was defined with consideration on different factors. And then the propagation law of underground deep-hole blasting vibration was researched. Finally, the maximum explosive charge fired at the same time which corresponds to the blast center distance was figured out. It has a certain reference value for blasting vibration control of underground deep-hole and the similar projects.(4) It used the DEM simulation software UDEC to simulate the process of drilling chamber’s wall rock collapse and fall. Through defining wall rock in different development degree and loading different blasting vibration, we can analyse the influence of blasting vibration on underground chambers. The results show that, when critical reduction factor of the space of joints, internal friction angles and cohesive strengths were1.67,1.83and1.36times of initial values respectively, drilling chamber’s wall rock began to collapse. When critical reduction factor of peak partical velocity(PPV) and duration of blasting seismic waves were0.5and5.0times of initial values respectively, drilling chamber’s wall rock began to collapse. Combination of anchorage and shotcrete support can improve weightless rock mass underground chambers’ safety load-carrying ability and explosion protection ability efficiency.