| The use of smooth blasting in peripheral eyes is a common method in tunnel blasting construction.It is obvious to use the characteristics of hydraulic blasting to carry out smooth blasting,which can improve the half hole rate and improve the effect of smooth blasting.By using ANSYS/LS-DYNA finite element analysis software,a single hole model is established to simulate the penetration process of single hole explosive rock.A double-hole model was established to analyze the process of fracture formation under different coupling conditions between explosive and gunhole.The blasting effect under different coupling conditions was compared and studied.Several factors affecting smooth blasting were simulated and analyzed,such as peripheral hole spacing,thickness of photoexplosive layer,charge line density,charge structure and so on.According to the principle of orthogonal test,nine groups of tests were designed based on the factors of the peripheral hole spacing,the thickness of the photoexplosive layer and the density of the line charge.Based on the analysis of the test results,the reasonable hole network parameters for the excavation of Dongqi tunnel are obtained.The optimum parameters suitable for smooth blasting in Dongqitunnel are obtained by analyzing the data of orthogonal test by means of visual analysis and variance analysis.The optimum peripheral hole spacing is0.45～0.5 m;the optimum thickness of blasting layer is 0.5～0.55 m;and the optimum linear charge density is 0.2～0.23 kg/m. |
