Research On Blasting Parameters Of Broken Complex Rock Mass Tunnel

Rock blasting technology is a significant rock crushing technology,the selection of parameters in rock blasting is very vital,which will not only affect the construction schedule,but also affect the construction cost.However,due to the complexity of the rock itself,it is difficult to quantitatively analyze,and the blasting parameters still need to be selected based on experience.Reasonable blasting technology and parameter design can effectively reduce the impact of blasting vibration on the surrounding rock loose circle,and can provide reference for the study of reducing the disturbance of surrounding rock and the blasting parameters.Therefore,in order to control the tunnel blasting effect,the tunnel blasting parameters are studied and the following results are obtained:(1)The rock crushing mechanism and the finite element numerical simulation software ANSYS / LS-DYNA software are researched,and the mechanical model and parameters suitable for tunnel blasting are selected.Based on the highway project of Guizhou Province,the tunnel blasting effect under different parameters was studied.(2)Combined with the characteristics and requirements of the auxiliary eye,establish a numerical model of the auxiliary eye,and study the three parameters of the uncoupling coefficient of the hole,the distance between the holes,and the row spacing of the holes.Validate the grid independence of the model,and obtain the values of uncoupling coefficient,blast hole spacing,and row spacing that have achieved good results during auxiliary eye blasting according to the tunnel surrounding rock fracture and crack development and the surrounding rock disturbance,perform blast vibration velocity prediction.(3)Combine the characteristics and requirements of the peripheral eye,establish a numerical model of the peripheral eye,and select the two parameters of the uncoupling coefficient of the peripheral hole and the distance between the holes.Through the analysis of the numerical simulation results,according to the degree of rock breakage and the damage range,the values of the uncoupling coefficient and the spacing parameter for obtaining a good blasting effect in the peripheral eye blasting are obtained,and the blasting vibration velocity is further predicted.(4)In actual engineering,there are broken zones in some tunnel sections.Add the numerical simulation model to the broken zone,and set four different angles for the broken zone.Analyze the impact of the broken zone angles on the blasting of the tunnel,and make reasonable suggestions for the actual project.(5)Scheme design and key technology research on tunnel blasting,on-site parameter setting and adjustment based on design scheme and numerical simulation parameters,can achieve good blasting effect.